Fit and suspension systems and methods for a mobile robot

ABSTRACT

An exoskeleton system comprising a leg actuator unit that is configured to be coupled to a leg of a user. The leg actuator unit includes: an upper arm and a lower arm that are rotatably coupled via a rotatable joint, the rotatable joint configured to be positioned at a knee of the user with the upper arm coupled about an upper-leg portion of the user above the knee and with the lower arm coupled about a lower-leg portion of the user below the knee. The upper arm is configured to be coupled to the upper-leg portion above the knee via a first set of couplers that includes a first upper-leg coupler, the lower arm is configured to be coupled to the lower-leg portion below the knee via a second set of couplers that includes one or more lower-leg couplers associated with a lower-leg brace, and an actuator extends between the upper arm and lower arm, the actuator configurable to move the upper arm and lower arm.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a non-provisional of and claims priority to U.S. Provisional Patent Application No. 63/030,586, filed May 27, 2020, entitled “POWERED DEVICE FOR IMPROVED USER MOBILITY AND MEDICAL TREATMENT,” with attorney docket number 0110496-010PRO. This application is hereby incorporated herein by reference in its entirety and for all purposes.

This application is a non-provisional of and claims priority to U.S. Provisional Patent Application No. 63/058,825, filed Jul. 30, 2020, entitled “POWERED DEVICE TO BENEFIT A WEARER DURING TACTICAL APPLICATIONS,” with attorney docket number 0110496-011PRO. This application is hereby incorporated herein by reference in its entirety and for all purposes.

This application is a non-provisional of and claims priority to U.S. Provisional Patent Application No. 63/129,010, filed Dec. 22, 2020, entitled “FIT AND SUSPENSION SYSTEM AND METHOD FOR A KNEE ORTHOSIS,” with attorney docket number 0110496-012PRO. This application is hereby incorporated herein by reference in its entirety and for all purposes.

This application is also related to U.S. Non-Provisional Applications filed the same day as this application having attorney docket numbers 0110496-010US0, 0110496-013US0, 0110496-014US0, 0110496-015US0, 0110496-016US0, 0110496-017US0 respectively entitled “POWERED MEDICAL DEVICE AND METHODS FOR IMPROVED USER MOBILITY AND TREATMENT”, “BATTERY SYSTEMS AND METHODS FOR A MOBILE ROBOT”, “CONTROL SYSTEM AND METHOD FOR A MOBILE ROBOT”, “USER INTERFACE AND FEEDBACK SYSTEMS AND METHODS FOR A MOBILE ROBOT”, “DATA LOGGING AND THIRD-PARTY ADMINISTRATION OF A MOBILE ROBOT” and “MODULAR EXOSKELETON SYSTEMS AND METHODS” and having respective application numbers XX/YYY,ZZZ, XX/YYY,ZZZ, XX/YYY,ZZZ, XX/YYY,ZZZ, XX/YYY,ZZZ and XX/YYY,ZZZ, These applications are hereby incorporated herein by reference in their entirety and for all purposes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an example illustration of an embodiment of an exoskeleton system being worn by a user.

FIG. 2 is a front view of an embodiment of a leg actuation unit coupled to one leg of a user.

FIG. 3 is a side view of the leg actuation unit of FIG. 3 coupled to the leg of the user.

FIG. 4 is a perspective view of the leg actuation unit of FIGS. 3 and 4.

FIG. 5 is a block diagram illustrating an example embodiment of an exoskeleton system.

FIG. 6 is a rear view of another embodiment of an exoskeleton system including a leg actuator unit coupled to the right leg of a user.

FIG. 7 is a close-up view of a portion of the illustration of FIG. 6.

FIG. 8 is a side view of the embodiment of the exoskeleton system of FIGS. 6 and 7.

FIG. 9 is a front view of the exoskeleton system of FIGS. 6-8.

FIG. 10 is a perspective view of the leg actuation unit shown in FIGS. 6-9.

FIG. 11 illustrates a front view of an embodiment of an actuator unit that comprises a knee-joint-spanning strap assembly.

FIG. 12 illustrates a side view of the embodiment of the actuator unit of FIG. 12.

FIG. 13a illustrates a side view of a pneumatic actuator in a compressed configuration in accordance with one embodiment.

FIG. 13b illustrates a side view of the pneumatic actuator of FIG. 13a in an expanded configuration.

FIG. 14a illustrates a cross-sectional side view of a pneumatic actuator in a compressed configuration in accordance with another embodiment.

FIG. 14b illustrates a cross-sectional side view of the pneumatic actuator of FIG. 14a in an expanded configuration.

FIG. 15a illustrates a top view of a pneumatic actuator in a compressed configuration in accordance with another embodiment.

FIG. 15b illustrates a top view of the pneumatic actuator of FIG. 15a in an expanded configuration.

FIG. 16 illustrates a top view of a pneumatic actuator constraint rib in accordance with an embodiment.

FIG. 17a illustrates a cross-sectional view of a pneumatic actuator bellows in accordance with another embodiment.

FIG. 17b illustrates a side view of the pneumatic actuator of FIG. 17a in an expanded configuration showing the cross section of FIG. 17 a.

FIG. 18 illustrates an example planar material that is substantially inextensible along one or more plane axes of the planar material while being flexible in other directions.

It should be noted that the figures are not drawn to scale and that elements of similar structures or functions are generally represented by like reference numerals for illustrative purposes throughout the figures. It also should be noted that the figures are only intended to facilitate the description of the preferred embodiments. The figures do not illustrate every aspect of the described embodiments and do not limit the scope of the present disclosure.

DETAILED DESCRIPTION

The following disclosure also includes example embodiments of the design of novel exoskeleton devices. Various preferred embodiments include: a leg brace with integrated actuation, a mobile power source and a control unit that determines the output behavior of the device in real-time.

A component of an exoskeleton system that is present in various embodiments is a body-worn, lower-extremity brace that incorporates the ability to introduce torque to the user. One preferred embodiment of this component is a leg brace that is configured to support the knee of the user and includes actuation across the knee joint to provide assistance torques in the extension direction. This embodiment can connect to the user through a series of attachments including one on the boot, below the knee, and along the user's thigh. This preferred embodiment can include this type of leg brace on both legs of the user.

The present disclosure teaches example embodiments of a fluidic exoskeleton system that includes one or more adjustable fluidic actuators. Some preferred embodiments include a fluidic actuator that can be operated at various pressure levels with a large stroke length in a configuration that can be oriented with a joint on a human body.

This disclosure also includes example embodiments of a novel fit architecture that is able to fit and suspend a device being worn on the leg of a user. Systems and methods described herein can have application to the development of fit systems for powered devices that are worn on the user's leg to provide supplemental torques at the knee for a variety of application areas which can include recreation, military, first responders, or health. In each of these applications the need exists in various examples to wear a system external to the body that has a requirement to stay relatively located with the targeted joint of the user. A desirable aspect of various embodiments can be for the fit system to both comfortably keep the device constrained to the user's leg, and to securely prevent the device from falling down the user's leg by resisting the downward force of gravity. This disclosure describes various embodiments of such fit systems and methods and their integration into an exoskeleton or mobile robot.

In one aspect, this disclosure teaches methods for developing and implementing various embodiments for fit systems to keep a brace on a user and aligned with the targeted joint. One preferred embodiment includes a fit system to affix a lower extremity powered exoskeleton device that aligns with the user's knee. This embodiment can be designed to securely fix the leg brace structure to the leg. It should be noted that throughout this disclosure we will use such an embodiment as one central example for discussion; however, it should not be viewed as limiting in the scope or applicability of the invention. Other specific embodiments can provide great value to include, but are not limited to, passive orthotic bracing, resistive custom fabricated bracing, or unpowered recreational equipment.

At the center of some examples can be a series of objectives for the fit system. One such example objective for the fit system can be to prevent translation of the joint on the brace in relation to the user's leg (e.g., prevent translation in the transverse plane). Another example objective for the fit system can be to prevent the brace from sagging down the leg as a result of gravity over the course of normal use (e.g., prevent sag in the sagittal plane). It should be noted that these objectives are representative of the goals for these devices and not intended to be fully descriptive of all strapping goals and some strapping goals can be absent in some examples. Other embodiments can include but are not limited to preventing the brace from rotating around the leg of the user. Various embodiments of fit systems have the target goals of meeting different objectives, however, they can include either or both of the above objectives. Alternative embodiments can include any variety of additional fit system objectives as a requirement of the specific application.

A preferred embodiment can be targeting solving both an alignment objective and a suspension objective. Such embodiment can use a strap connected at the lower leg just above the ankle in some examples. For example, this strap can be firmly placed in a supra-malleolar location that is located above the malleolus (protruding bones at the ankle) and below the bulk of the calf muscle. This strap can be connected in a firm connection such that it lies in the narrowing diameter portion of the user's leg. This connection method can present a unique benefit over other systems because some embodiments have no portion of the design extending below the ankle to interface with the user's foot or the ground. Avoiding the need for the brace to provide suspension through connection to the shoe or integration into the shoe can, in some examples, improve the user experience, increase longevity of the shoe, and can provide versatility of footwear. It should be noted that other embodiments can include adjustments to the position of an ankle strap, adjustments to the design of a supra-malleolar strap, and/or integration of the supra-malleolar strap along with other suitable suspension or strapping configurations. Such example modifications are discussed in more detail below.

As discussed herein, an exoskeleton system 100 can be configured for various suitable uses. For example, FIGS. 1-3 illustrate an exoskeleton system 100 being used by a user. As shown in FIG. 1 the user 101 can wear the exoskeleton system 100 on both legs 102. FIGS. 2 and 3 illustrate a front and side view of an actuator unit 110 coupled to a leg 102 of a user 101 and FIG. 4 illustrates a side view of an actuator unit 110 not being worn by a user 101.

As shown in the example of FIG. 1, the exoskeleton system 100 can comprise a left and right leg actuator unit 110L, 110R that are respectively coupled to a left and right leg 102L, 102R of the user. In various embodiments, the left and right leg actuator units 110L, 110R can be substantially mirror images of each other.

As shown in FIGS. 1-4, leg actuator units 110 can include an upper arm 115 and a lower arm 120 that are rotatably coupled via a joint 125. A bellows actuator 130 extends between the upper arm 115 and lower arm 120. One or more sets of pneumatic lines 145 can be coupled to the bellows actuator 130 to introduce and/or remove fluid from the bellows actuator 130 to cause the bellows actuator 130 to expand and contract and to stiffen and soften, as discussed herein. A backpack 155 can be worn by the user 101 and can hold various components of the exoskeleton system 100 such as a fluid source, control system, a power source, and the like.

As shown in FIGS. 1-3, the leg actuator units 110L, 110R can be respectively coupled about the legs 102L, 102R of the user 101 with the joints 125 positioned at the knees 103L, 103R of the user 101 with the upper arms 115 of the leg actuator units 110L, 110R being coupled about the upper-legs portions 104L, 104R of the user 101 via one or more couplers 150 (e.g., straps that surround the legs 102). The lower arms 120 of the leg actuator units 110L, 110R can be coupled about the lower-leg portions 105L, 105R of the user 101 via one or more couplers 150.

The upper and lower arms 115, 120 of a leg actuator unit 110 can be coupled about the leg 102 of a user 101 in various suitable ways. For example, FIGS. 1-3 illustrates an example where the upper and lower arms 115, 120 and joint 125 of the leg actuator unit 110 are coupled along lateral faces (sides) of the top and bottom portions 104, 105 of the leg 102. As shown in the example of FIGS. 1-3, the upper arm 115 can be coupled to the upper-leg portion 104 of a leg 102 above the knee 103 via two couplers 150 and the lower arm 120 can be coupled to the lower-leg portion 105 of a leg 102 below the knee 103 via two couplers 150.

Specifically, upper arm 115 can be coupled to the upper-leg portion 104 of the leg 102 above the knee 103 via a first set of couplers 250A that includes a first and second coupler 150A, 150B. The first and second couplers 150A, 150B can be joined by a rigid plate assembly 215 disposed on a lateral side of the upper-leg portion 104 of the leg 102, with straps 151 of the first and second couplers 150A, 150B extending around the upper-leg portion 104 of the leg 102. The upper arm 115 can be coupled to the plate assembly 215 on a lateral side of the upper-leg portion 104 of the leg 102, which can transfer force generated by the upper arm 115 to the upper-leg portion 104 of the leg 102.

The lower arm 120 can be coupled to the lower-leg portion 105 of a leg 102 below the knee 103 via second set of couplers 250B that includes a third and fourth coupler 150C, 150D. A coupling branch unit 220 can extend from a distal end of, or be defined by a distal end of the lower arm 120. The coupling branch unit 220 can comprise a first branch 221 that extends from a lateral position on the lower-leg portion 105 of the leg 102, curving upward and toward the anterior (front) of the lower-leg portion 105 to a first attachment 222 on the anterior of the lower-leg portion 105 below the knee 103, with the first attachment 222 joining the third coupler 150C and the first branch 221 of the coupling branch unit 220. The coupling branch unit 220 can comprise a second branch 223 that extends from a lateral position on the lower-leg portion 105 of the leg 102, curving downward and toward the posterior (back) of the lower-leg portion 105 to a second attachment 224 on the posterior of the lower-leg portion 105 below the knee 103, with the second attachment 224 joining the fourth coupler 150D and the second branch 223 of the coupling branch unit 220.

As shown in the example of FIGS. 1-3, the fourth coupler 150D can be configured to surround and engage the boot 191 of a user. For example, the strap 151 of the fourth coupler 150D can be of a size that allows the fourth coupler 150D to surround the larger diameter of a boot 191 compared to the lower portion 105 of the leg 102 alone. Also, the length of the lower arm 120 and/or coupling branch unit 220 can be of a length sufficient for the fourth coupler 150D to be positioned over a boot 191 instead of being of a shorter length such that the fourth coupler 150D would surround a section of the lower portion 105 of the leg 102 above the boot 191 when the leg actuator unit 110 is worn by a user.

Attaching to the boot 191 can vary across various embodiments. In one embodiment, this attachment can be accomplished through a flexible strap that wraps around the circumference of boot 191 to affix the leg actuator unit 110 to the boot 191 with the desired amount of relative motion between the leg actuator unit 110 and the strap. Other embodiments can work to restrict various degrees of freedom while allowing the desired amount of relative motion between the leg actuator unit 110 and the boot 191 in other degrees of freedom. One such embodiment can include the use of a mechanical clip that connects to the back of the boot 191 that can provide a specific mechanical connection between the device and the boot 191. Various embodiments can include but are not limited to the designs listed previously, a mechanical bolted connection, a rigid strap, a magnetic connection, an electro-magnetic connection, an electromechanical connection, an insert into the user's boot, a rigid or flexible cable, or a connection directly to the boot, or the like.

Another aspect of the exoskeleton system 100 can be fit components used to secure the exoskeleton system 100 to the user 101. Since the function of the exoskeleton system 100 in various embodiments can rely heavily on the fit of the exoskeleton system 100 efficiently transmitting forces between the user 101 and the exoskeleton system 100 without the exoskeleton system 100 significantly drifting on the body 101 or creating discomfort, improving the fit of the exoskeleton system 100 and monitoring the fit of the exoskeleton system 100 to the user over time can be desirable for the overall function of the exoskeleton system 100 in some embodiments.

In various examples, different couplers 150 can be configured for different purposes, with some couplers 150 being primarily for the transmission of forces, with others being configured for secure attachment of the exoskeleton system 100 to the body 101. In one preferred embodiment for a single knee system, a coupler 150 that sits on the lower-leg 105 of the user 101 (e.g., one or both of couplers 150C, 150D) can be intended to target body fit, and as a result, can remain flexible and compliant to conform to the body of the user 101. Alternatively, in this embodiment a coupler 150 that affixes to the front of the user's thigh on an upper portion 104 of the leg 102 (e.g., one or both of couplers 150A, 150B) can be intended to target power transmission needs and can have a stiffer attachment to the body than other couplers 150 (e.g., one or both of couplers 150C, 150D). Various embodiments can employ a variety of strapping or coupling configurations, and these embodiments can extend to include any variety of suitable straps, couplings, or the like, where two parallel sets of coupling configurations are meant to fill these different needs.

In some cases the design of the joint 125 can improve the fit of the exoskeleton system 100 on the user. In one embodiment, the joint 125 of a single knee leg actuator unit 110 can be designed to use a single pivot joint that has some deviations with the physiology of the knee joint. Another embodiment, uses a polycentric knee joint to better fit the motion of the human knee joint, which in some examples can be desirably paired with a very well fit leg actuator unit 110. Various embodiments of a joint 125 can include but are not limited to the example elements listed above, a ball and socket joint, a four bar linkage, and the like.

Some embodiments can include fit adjustments for anatomical variations in varus or valgus angles in the lower-leg 105. One preferred embodiment includes an adjustment incorporated into a leg actuator unit 110 in the form of a cross strap that spans the joint of the knee 103 of the user 101, which can be tightened to provide a moment across the knee joint in the frontal plane which varies the nominal resting angle. Various embodiments can include but are not limited to the following: a strap that spans the joint 125 to vary the operating angle of the joint 125; a mechanical assembly including a screw that can be adjusted to vary the angle of the joint 125; mechanical inserts that can be added to the leg actuator unit 110 to discreetly change the default angle of the joint 125 for the user 101, and the like.

In various embodiments, the leg actuator unit 110 can be configured to remain suspended vertically on the leg 102 and remain appropriately positioned with the joint of the knee 103. In one embodiment, coupler 150 associated with a boot 191 (e.g., coupler 150D) can provide a vertical retention force for a leg actuator unit 110. Another embodiment uses a coupler 150 positioned on the lower-leg 105 of the user 101 (e.g., one or both of couplers 150C, 150D) that exerts a vertical force on the leg actuator unit 110 by reacting on the calf of the user 101. Various embodiments can include but are not limited to the following: suspension forces transmitted through a coupler 150 on the boot (e.g., coupler 150D) or another embodiment of the boot attachment discussed previously; suspension forces transmitted through an electronic and/or fluidic cable assembly; suspension forces transmitted through a connection to a waist belt; suspension forces transmitted through a mechanical connection to a backpack 155 or other housing for the exoskeleton device 510 and/or pneumatic system 520 (see FIG. 5); suspension forces transmitted through straps or a harness to the shoulders of the user 101, and the like.

In various embodiments, a leg actuator unit 110 can be spaced apart from the leg 102 of the user with a limited number of attachments to the leg 102. For example, in some embodiments, the leg actuator unit 110 can consist or consist essentially of three attachments to the leg 102 of the user 101, namely via the first and second attachments 222, 224 and 215. In various embodiments, the couplings of the leg actuator unit 110 to the lower-leg portion 105 can consist or consist essentially of a first and second attachment on the anterior and posterior of the lower-leg portion 105. In various embodiments, the coupling of the leg actuator unit 110 to the upper-leg portion 104 can consist or consist essentially of a single lateral coupling, which can be associated with one or more couplers 150 (e.g., two couplers 150A, 150B as shown in FIGS. 1-4). In various embodiments, such a configuration can be desirable based on the specific force-transfer for use during a subject activity. Accordingly, the number and positions of attachments or coupling to the leg 102 of the user 101 in various embodiments is not a simple design choice and can be specifically selected for one or more selected target user activities.

Turning to FIGS. 6-10, another embodiment of an exoskeleton system 100 is illustrated. In this example embodiment, the exoskeleton system 100 includes a single right leg actuator unit 110; however, it should be clear that this example embodiment can be extended to an exoskeleton system 100 having both a left and right actuator unit 110L, 110R or only a left actuator unit 110L. Accordingly the example of FIGS. 6-10 should not be construed as limiting, and in further embodiments, any suitable elements can be present in a suitable plurality, absent, interchanged with elements of other embodiments (e.g., FIGS. 1-4), or the like.

As shown in FIGS. 6-10, the leg actuator unit 110 can include an upper arm 115 and a lower arm 120 that are rotatably coupled via a joint 125. A bellows actuator 130 extends between the upper arm 115 and lower arm 120. One or more sets of pneumatic lines 145 can be coupled to the bellows actuator 130 to introduce and/or remove fluid from the bellows actuator 130 to cause the bellows actuator 130 to expand and contract and to stiffen and soften, as discussed herein. A backpack 155 can be worn by the user 101 (see FIGS. 6, 8 and 9) and can hold various components of the exoskeleton system 100 such as a fluid source, control system, a power source, exoskeleton device, pneumatic system, and the like as discussed herein.

As shown in FIGS. 6-9, the leg actuator unit 110 can be coupled about the right leg of the user 101 with the joint 125 positioned at the right knee 103R of the user 101 (see FIGS. 1-3 for labeling of body parts of the user 101), with the upper arm 115 of the leg actuator unit 110R being coupled about the right upper-leg portion 104R of the user 101 via one or more couplers 150 (e.g., straps that surround the legs 102). The lower arm 120 of the leg actuator unit 110 can be coupled about the right lower-leg portion 105R of the user 101 via one or more couplers 150.

The upper and lower arms 115, 120 of a leg actuator unit 110 can be coupled about the leg 102 of a user 101 in various suitable ways. For example, FIGS. 6-9 illustrate an example where the upper and lower arms 115, 120 and joint 125 of the leg actuator unit 110 are coupled along lateral faces (sides) of the top and bottom portions 104, 105 of the leg 102. As shown in the example of FIGS. 6-9, the upper arm 115 can be coupled to the upper-leg portion 104 of a leg 102 above the knee 103 via one coupler 150 and the lower arm 120 can be coupled to the lower-leg portion 105 of a leg 102 below the knee 103 via two couplers 150.

Specifically, upper arm 115 can be coupled to the upper-leg portion 104 of the leg 102 above the knee 103 via a first upper-leg coupler 150A. The first upper-leg coupler 150A can be associated with a rigid upper-leg brace 615 disposed on and engaging a lateral side of the upper-leg portion 104 of the leg 102, with a strap of the first upper-leg coupler 150A extending around the upper-leg portion 104 of the leg 102. The upper arm 115 can be coupled to the rigid upper-leg brace 615 on a lateral side of the upper-leg portion 104 of the leg 102, which can transfer force generated by the upper arm 115 to the upper-leg portion 104 of the leg 102.

The lower arm 120 can be coupled to the lower-leg portion 105 of a leg 102 below the knee 103 via a second set of couplers 650 that includes first and second lower-leg couplers 150C, 150D. The first and second lower-leg couplers 150C, 150D can be associated with a rigid lower-leg brace 620 disposed on and engaging a lateral side of the lower-leg portion 105 of the leg 102. The lower arm 120 can be coupled to the rigid lower-leg brace 620 on a lateral side of the lower-leg portion 105 of the leg 102, which can transfer force generated by the lower arm 120 to the lower-leg portion 105 of the leg 102. The rigid lower-leg brace 620 can extend downward from a coupling with the lower arm 120 at a lateral position on the lower-leg portion 105 of the leg 102, with a portion of the rigid lower-leg brace 620 curving toward the posterior (back) of the lower-leg portion 105 to attachments 622, 624 that couple one or more portions of the first and second lower-leg couplers 150C, 150D to the rigid lower-leg brace 620.

The first lower-leg coupler 150C can include a calf-coupling assembly 630 that includes a calf brace 632 that is coupled to the rigid lower-leg brace 620 via a first, second and third calf strap 634, 636, 638. For example, as shown in the example of FIGS. 6 and 7, the first and second calf straps 634, 636 can extend horizontally from opposing lateral sides of an upper portion of the rigid lower-leg brace 620 from an internal face of the rigid lower-leg brace 620. The third calf strap 638 can extend vertically from a lower posterior portion of the rigid lower-leg brace 620 from an internal face of the rigid lower-leg brace 620 where the third calf strap 638 is coupled to the rigid lower-leg brace 620 via a first set of one or more attachments 622. In various embodiments, the calf brace 632 can be a rigid or flexible element and can comprise materials such as a fabric, plastic, carbon-fiber, or the like.

The calf straps 634, 636, 638 can be configured in various suitable ways and can include various suitable mechanisms that allow the calf straps 634, 636, 638 to be tightened, loosened, extended, shortened, or the like. For example, in some embodiments, the first and second calf straps 634, 636 comprise hook and loop tape (e.g., Velcro) that allows the second calf straps 634, 636 to be tightened, loosened, extended, shortened, or the like. In some embodiments, the third calf strap 638 can comprise a strap cinch, or the like, that allows the third calf strap 638 to be tightened, loosened, extended, shortened, or the like.

The second lower-leg coupler 150D can comprise an ankle-coupling assembly 640 that includes a cuff 642 that extends around and surrounds the lower-leg portion 105 above the ankle of the user 101 and held via an ankle strap 644. The cuff 642 can be coupled to the rigid lower-leg brace 620 via one or more coupling tabs 646 that extend vertically from the cuff 642, with the one or more coupling tabs 646 coupled to the rigid lower-leg brace 620 via a second set of one or more attachments 624 on an internal face of the rigid lower-leg brace 620. The ankle strap 644 can include various suitable elements that allow the ankle strap to be tightened, loosened, extended, shortened, or the like (e.g., hook and loop tape, strap cinch, or the like).

In various embodiments, the rigid upper-leg and lower-leg braces 615, 620 can be made of various suitable materials such as a plastic, carbon-fiber, metal, wood, or the like. As discussed herein, in some embodiments the upper-leg and/or lower-leg braces 615, 620 can be formed to match the contours of the legs 102 of the user 101, which can be desirable for increasing comfort for the user 101 maximizing surface area of the upper-leg and/or lower-leg braces 615, 620 engaging the legs 102 of the user 101, and the like. In some examples, the upper-leg and/or lower-leg braces 615, 620 can be formed specifically for a given user 101, which can include molding to user body parts, scanning the user's body and generating upper-leg and/or lower-leg braces 615, 620 from such scan data, and the like.

In some embodiments, alignment and suspension of one or more actuation units 110 on the leg 102 (or other body parts) of a user 101 can be achieved in some examples via a strap connected at the lower-leg 105 just above the ankle of the user 101. For example, such a strap can be firmly placed in a supra-malleolar location that is located above the malleolus (protruding bones at the ankle) and below the bulk of the calf muscle. Such a strap can be connected in a firm connection such that it lies in a narrowing diameter portion of the user's leg 102. For example, coupler 150D of FIGS. 1-4 and 6-10 and/or ankle coupling assembly 640 of FIGS. 6-10 can be configured in such a way. Such a connection method can be beneficial in some examples by having no portion of the actuator unit 110 (or at least no substantive portion used for coupling) extending below the ankle of the user 101 to interface with the user's foot, the ground, or area below the malleolus.

Avoiding the need for an actuator unit 110 to provide support and/or suspension through connection to the shoe or integration into the shoe can improve the user experience, increase longevity of the shoe, and can provide versatility of footwear in various examples. It should be noted that other embodiments can include adjustments to the position of such an ankle strap; adjustments to the design of a supra-malleolar strap, or integration of a supra-malleolar strap along with other suitable suspension or strapping configurations. Such example modifications are discussed herein in more detail.

One component of a supra-malleolar strap can be an attachment between a flexible, rigid, or semi-rigid strap (e.g., cuff 642) and the structure of a rigid brace (e.g., lower-leg brace 620). There are a variety of suitable ways to attach a supra-malleolar strap to a rigid brace which can each present unique advantages in various embodiments. In one embodiment, a strap can be connected to a rigid brace structure through a single point connection (e.g. a single tab 646). In various examples, such a connection can be configured to provide resistance to translation of the strap relative to the rigid brace, but may not introduce resistance to rotational movement between the strap (which can be firmly affixed to the user) and the brace structure. In another embodiment, an interface material supporting the supra-malleolar strap can be substantially less rigid than the brace structure and the interface material can in some examples be configured such that the interface material can transfer vertically oriented forces to the rigid brace structure of the device while allowing for side to side and rotational movement.

Using the embodiment of FIGS. 6-10 as an example, a semi-rigid cuff 642 can be coupled to a rigid lower-leg brace 620 via one or more tabs 646 that are inextensible along an axis of coupling between the rigid lower-leg brace 620 respective of one or more tabs 646, while the tabs 646 are flexible about such an axis of coupling. For example, in one embodiment, the one or more tabs 646 can be planar and elongated and made out of a material such as plastic or carbon fiber that is inextensible along the length of the planar and elongated tab(s) 646, but the one or more tabs 646 can be of a thickness such that the one or more tabs 646 are flexible and above to curl, flex, rotate, or bend about the length of the tab 646 to provide for side to side and/or rotational movement of the foot of a user.

In this way, such an embodiment structure may be configured to accomplish the objective of blocking translation between respective elements (e.g., between a rigid lower-leg brace 620 and cuff 642, while being able to accommodate motion at and around the ankle as well as variation in clothing and footwear. In some embodiments, an ankle strap can be connected to a rigid brace structure through two or more vertically aligned attachment points. For example, as shown in the example of FIGS. 6-10, a cuff 642 can be coupled to the rigid lower-leg brace 620 via a first and second tab 646 with respective sets of vertically aligned attachments 624.

Such an attachment (e.g., via one or more attachments 624), in some examples, can provide a resistance to translation in all axes and then only produce sagittal plane resistance to rotation. A variety of related embodiments exist and should not be limited by the examples presented above. These include but are not limited to any combination of attachment methods that produces resistance to motion in any of the three cartesian directions or any of the three rotational directions. Some embodiments can also select but are not limited to one or more of the following types of resistance: locking all motion, mechanically resisted motion, free motion, substantially non-linear resistance to motion, selectively powered resistance to motion, and the like.

In various embodiments the location of a supra-malleolar strap can be important to the overall function of a fit system. For example, in some embodiments, it can be desirable for the ankle strap to be located at or near the smallest diameter location of the user's leg that is located below the calf and above the malleoli of the ankle. This portion of the user's leg, in various examples, can have the potential to provide a secure and comfortable reaction to contact forces in some or all directions to help resist motion in some or all three cartesian axes and some or all three rotational axes. There can be variability in the location for an individual user up and down on the user's leg, however, in some examples, the functionality begins to degrade as an ankle strap is located so high that the circumference of the user's calf is dictating the strap diameter, or so low that the pressure from the strap is being transferred to the malleoli.

For some users in some examples, this can result in a range of positional flexibility that is near, but not strictly limited to, one inch up or down from an ideal location. In various examples, as an ankle strap is located too far down the leg, a failure modality can be that of pain experienced by the user as a result of pressure points on sensitive tissue. For example, in some embodiments, if an ankle strap is located too far up the leg, a failure mode can be the ankle strap slipping down the leg to a smaller diameter portion of the user's lower leg.

Another component of a supra-malleolar ankle strap in some embodiments can include the mechanical design of the strap itself. In one preferred embodiment, an ankle strap can be constructed out of substantially inextensible material to enable the ankle strap to transmit targeted loads without creating much relative motion between the user's leg and a rigid brace that the ankle strap is coupled to. In some examples, an ankle strap can be constructed out of a semi-rigid material that allows the leg actuator unit 110 to disperse contact loads borne by the ankle strap around the circumference of the user's leg. Distributing these forces can have the benefit of reducing the contact pressures experienced by the user in an effort to reduce pain, increase comfort, and the like. The use of a semi-rigid ankle strap material may also provide benefits during large range of motion behaviors in various embodiments. In some examples, the geometry of the leg of the user, including the diameter of the supra-malleolar segment, can vary throughout the range of motion due both to kinematic constraints and the engagement of the muscle. By providing a semi-rigid interface in various embodiments, an ankle strap may be able to avoid a kinematic mismatch between a rigid brace member and the user due to being over-constrained.

To further target force distribution, in some embodiments an ankle strap can include contact padding that allows a rigid brace member to target specific areas of the body of the user to localize contact forces. In some embodiments, this can be accomplished by including padding in the ankle strap at the locations of desired contact pressure such that the ankle strap makes little to no contact with the leg in areas that are uniquely sensitive such as the tendon locations. There are many variants of an ankle strap design and the description above should not be viewed as limiting in any way. Further alternative embodiments can include but are not limited to straps constructed of entirely rigid material, straps constructed of entirely compliant material, straps constructed out of partially extensible material, straps with significantly nonlinear extensibility properties, straps that pass through or otherwise support semi-rigid or rigid interface cuffs designed to broaden the areas of pressure distribution, and straps with padding added directly to the areas of potential discomfort to reduce the contact pressure at those locations.

In some embodiments, it can be desirable to integrate a supra-malleolar strap along with other suitable fit and/or suspension techniques. In one embodiment, a supra-malleolar strap can be connected to the leg of a user along with circumferential coupling straps distributed along the lower leg and upper leg of the user (e.g., such as couplings 150A, 150B of FIGS. 1-4 or coupling 150A of FIGS. 6-10). In another embodiment, a supra-malleolar strap can be incorporated along with a contact-to-ground portion of a rigid brace member in an effort to apply additional vertical force to assist with suspension of the leg actuator unit 110 on the leg of the user. Other embodiments can include but are not limited to integration of an AFO (Ankle Foot Orthosis), integration of a hip strap connecting up to the belt of the user, integration of suspenders to the shoulders, and/or integration of a cross-body hip strap for vertical suspension.

Another design component of some embodiments can be the inclusion of one or more adjustment elements to tailor the location of a supra-malleolar strap on more users. In one preferred embodiment, such adjustment elements can be integrated into a rigid brace component of a leg actuation unit 110 that can be aligned to the user's lower leg such that one or more adjustments allow the operator to adjust the distance between the supra-malleolar strap relative to the knee of the user. Such one or more adjustment elements can allow a small collection of device sizes to adequately meet the size requirements of a wide range of users. In another embodiment, the adjustment can be accounted for in the design of a semi-rigid supra-malleolar strap itself such that no adjustment is required within the rigid mechanical structure. There are plenty of other embodiments for the integration of adjustment elements that can include but are not limited to: the use of sizes to mitigate the range of adjustments needed for every specific device, the use of telescoping or expandable device components, the use of custom-sized interface components to accommodate for the mechanical differences between users, and the like.

In some example cases, the included adjustment elements may not be sufficient to accommodate for the proper fit of all individual users. In one example, an exoskeleton device 100 is being fit to the leg of a user with a unique sensitivity to pain from contact pressure around his tendons on the front and back of his leg. To properly fit this user, it can be desirable for an ankle strap to support additional modifications to accommodate the unique pressure profile required by this example user. In such a case, one or more leg actuator units 110 can be fitted with extra-large padding to artificially increase the effective diameter of the semi-rigid ankle strap.

In various examples, this can allow the ankle strap not to contact the front or back portions of the user's leg at all, which can result in no or minimized contact force being transmitted through the sensitive portions of the user's skin. The benefit of an embodiment such as this can be that it allows a greater range of addressable users, without requiring additional modifications to the primary structure of one or more leg actuation units 110 which can be rigid and more expensive in some examples. In another embodiment, a portion of an ankle strap can be constructed out of a heat-formable material that can allow a practitioner to shape a semi-rigid portion of the ankle strap to alleviate the pressure at the areas of concern. A variety of other embodiments exist and the present disclosure should not be construed to be limited to just the examples listed above.

As discussed herein, fit components used to secure one or more actuation units 110 of an exoskeleton system 100 to a user 101. In some embodiments, the function of exoskeleton system 100 can rely heavily on the fit of the one or more actuation units 110 to efficiently transmit forces between the body of the user 101 and the one or more actuation units 110 without the one or more actuation units 110 significantly drifting on the body or creating discomfort. To this end, the efforts to improve the fit of the one or more actuation units 110 and monitor the fit of the one or more actuation units 110 on the body of the user over time can be desirable to the overall function of the exoskeleton system 100 in various examples.

One aspect of fitting one or more actuation units 110 to the body of a user that can improve the overall function of the exoskeleton system 100 in some examples can be to recognize that different straps often fill different needs on the one or more actuation units 110, with some straps being focused on the transmission of forces, and other straps being tailored towards the secure attachment of the one or more actuation units 110 to the body of the user. In one preferred example embodiment for a single-knee system, a one or more straps that sit on the lower-leg 105 of the user can be intended to target body fit, and as a result, can remain flexible and compliant to conform to the user's body (e.g., straps 150C and/or 150D). In some embodiments, one or more straps (e.g., straps 150A and/or 150B) that affix to the front of the user's thigh or upper-leg 104 can be configured to target power transmission needs and can be much stiffer than other straps. Various embodiments can employ a variety of suitable strapping configurations, and such embodiments can include any suitable variety of straps. For example, some embodiments can include two parallel sets of strapping configurations that are meant to fill these different needs.

In some embodiments, the design of the joint 125 of an actuator unit 110 can be important to improve the fit of the leg actuation unit 110 on the body of the user. In one example embodiment, the joint 125 of a single knee actuator unit 110 can be designed to use a single pivot joint that has some deviations with the physiology of the knee joint 103 of the user. Another example embodiment can use a polycentric knee joint 125 to better fit the motion of the human knee joint 103 which can be desirable paired, in some examples, with a very well fit actuator unit 110. Various embodiments of a joint 125 of a leg actuation unit 110 can include a ball-and-socket joint, a four-bar linkage, and the like.

Another aspect of fit components in various embodiments can be the overall fit strategy for accounting for variations among a population of users 101. Various preferred embodiments can accommodate such variability by providing a single size for a leg actuation unit 110 that can be adjusted on site to support a wide range of body shapes and sizes of desired users. Such an embodiment in some examples may fail to provide an ideal fit for all users, but is able to provide an acceptable fit for a sufficiently larger number of users, which can be desirable. Another embodiment can include a small range of different sizes (e.g., of actuation units 110) that are designed to better accommodate the variations of a smaller range of a target user segment. Further embodiments can use a detailed understanding of a specific user and/or the body of the user to produce a specifically tailored fit of one or more actuator units 110 for that single specific user. Such an embodiment can achieve this in some examples through the use of 3D scanning software that scans the user's leg and allows for the manufacture of one or more components of an actuation unit 110 that are specifically designed to fit the leg of an individual user (e.g., rigid braces 615, 620, calf brace 632, straps 150, or the like).

One aspect of fit components that is desirable in some embodiments can be the inclusion of adjustment elements for anatomical variations in varus or valgus angles in the lower-leg 105 of a user 101. For example, one preferred embodiment includes an adjustment element of an actuation unit 110 that comprises a cross-strap that spans the knee joint 103 of the user 101, which can be tightened (e.g., Velcro, strap cinch, or the like) to provide a moment across the knee joint 103 of the user 101 in the frontal plane, which can vary the nominal resting angle of the actuation unit 110 on the leg of the user. Various embodiments can include, but are not limited to one or more of the following: a strap that spans the knee joint 103 of the user 101 to vary the operating angle of the actuation unit 110 on the leg of the user; a mechanical assembly including a screw that can be adjusted to vary the operating angle of the actuation unit 110 on the leg of the user; and mechanical inserts that can be added to the actuation unit 110 to change default operating angles of the actuation unit 110 on the leg of the user.

For example, FIGS. 11 and 12 respectively illustrate a front and side view of an embodiment of an actuator unit 110 that comprises a knee-joint-spanning strap assembly 1100 that is coupled at a first end to a rigid upper-leg brace 615 on a lateral side of the upper leg 104 of the user 101 that extends downward and medially over the top of the knee 103 and couples to a third coupler 150C on a dorsal side of the lower-leg portion 105. The knee-joint-spanning strap assembly 1100 comprises straps 1102 and one or more strap couplers 1104 that allow the knee-joint-spanning strap assembly 1100 be tightened and loosened (e.g., Velcro, strap cinch, clip, buckle, or the like) to provide a moment across the knee joint 103 of the user 101 in the frontal plane, which can vary the nominal resting angle of the actuation unit 110 on the leg 102 of the user 101.

The ability of one or more leg actuation units 110 to remain suspended vertically on the limb of the user and remain appropriately positioned with the joint of interest (e.g., knee joint 103) can be another desirable aspect of fit components. One embodiment can comprise an ankle attachment to provide a vertical retention force for a leg actuation unit 110 (e.g., coupler 150D, ankle coupling assembly 640, supra-malleolar ankle strap, and the like). Another embodiment can comprise a strap positioned on the lower-leg 105 of the user 101 such that the strap can exert a vertical force on the leg actuation unit 110 by suspending on the calf of the user (e.g., coupler 150C, calf-coupling assembly 630, and the like).

Various embodiments can include, but are not limited to, one or more of the following: suspension forces transmitted through a strap on the ankle, suspension forces transmitted through an electronic and/or fluidic cable assembly (e.g., lines 145), suspension forces transmitted through a connection to a waist belt, suspension forces transmitted through a mechanical connection to a power supply component (e.g., power system 516), suspension forces transmitted through straps or a harness to the shoulders of the user, and suspension forces transmitted to the opposite hip of the user to place loads on the iliac crest of the pelvis.

In some embodiments, it can be desirable to verify a suitable fit of one or more leg actuator units 110 on the user's legs 102 to enable ideal operation and performance. One embodiment can include an external fit jig that can be held up to a user's leg 102 with a leg actuator unit 110 donned to determine where the fit of the actuator unit 110 is within or outside of allowable tolerances (i.e., whether the fit of the actuator unit 110 on the leg 102 is suitable). In various embodiments, such a mechanical jig can be used upon initial donning of one or more actuator units 110 or periodically throughout use of the exoskeleton system 100. Various embodiments include, but are not limited to, one or more of the following: external mechanical jig, software that observes performance of the system to identify proper fit, visual inspection tools that analyze a picture of one or more actuator units 110 on the user, a laser-guided fit system, and the like.

In some examples, (e.g., in a tactical scenario) it can be desirable for the user of an exoskeleton system 100 to be able to quickly doff the exoskeleton system 100 (e.g., to quickly remove one or both leg actuator units 110L, 110R if such actuators become damaged, run out of power, are no longer needed on a mission, malfunction, or otherwise impact the safety or comfort of the user) Some embodiments can comprise a quick-doff feature which can allow the user to quickly remove one or more portions of, or the entire exoskeleton system 100, in an effort to quickly evacuate the exoskeleton system 100 or portions thereof.

For example, one embodiment can include a quick-doff feature on a leg actuator unit 110 of the exoskeleton system 100 that with a pull of a single lever (or other suitable mechanism), all the straps, connectors, or the like that couple the leg actuator unit 110 to the leg 102 are disengaged and the leg actuator unit 110 can fall to the ground or otherwise be quickly removed by the user. Another embodiment can include a quick-doff feature on or about a power pack portion of an exoskeleton system 100 (e.g., on or about a backpack 155) with a single lever (or other suitable mechanism) that allows the user to drop a torso mounted power pack and keep one or more actuator units 110 affixed to the body of the user.

In some embodiments, a quick-doff feature can be a purely mechanical element, that physically disengages one or more couplings without electronic or computer elements. However, in some embodiments, a quick-doff feature can be electronically and/or computer operated. For example, in one embodiment, the exoskeleton device 510 can trigger one or more couplings of some or all portions of the exoskeleton system 100 to disengage (e.g., coupling of one or more leg actuation units 100, backpack 115, or the like). Various suitable couplings can be configured to be disengaged via one or more quick-doff features, such as one or more couplings 150 of a leg actuator unit 110, a line coupling 146, or the like.

One or more quick-doff features can be configured to allow the entire exoskeleton system 100 to be disengaged from the user, or allow one or more portions of the exoskeleton system 100 to be disengaged from the user. For example, in one embodiment a left leg actuator unit 110L can include a first quick-doff feature that allows the left leg actuator unit 110L to be disengaged from the user; a right leg actuator unit 110R can include a second quick-doff feature that allows the right leg actuator unit 110R to be disengaged from the user; and a backpack 155 can include a third quick-doff feature that allows the backpack 155 to be disengaged from the user. Some embodiments can include a fourth quick-doff feature (in addition to the first, second and third) that allows the left and right leg actuators 110L, 110R and backpack 155 to be disengaged all at once.

Various embodiments can include the examples listed above or combinations thereof. A variety of systems and methods for quick-doff mechanisms are within the scope and spirit of the present disclosure, so the examples herein should not be construed to be limiting. These can include but are not limited to a cable mechanism that is woven through straps of a leg actuator unit 110 that can be removed; a series of buckles that all engage on a single lever; a cable assembly that when pulled exerts force on the system in a variety of locations; an electrical button or switch that actuates a mechatronic or mechanical release, and the like. Such a release can cause a plurality of couplings to physically disengage substantially simultaneously, or in quick succession to allow one or more leg actuation units 110 to physically disengage from the user.

In some examples, it can be beneficial to modify the fit of the exoskeleton system 100 during use, which may be due to changes in the fit of the exoskeleton system 100 over time, changes in a task, mission or maneuver being performed by a user, or the like. For example, such changes can relate to various factors such as increasing or decreasing weight being born by the user and/or exoskeleton system 100; shifting of an actuator unit 110 on the body of a user that may naturally occur during use; portions of the user's body becoming raw or tired; different fit requirements based on different tasks, missions or maneuvers being performed by the user, and the like.

One embodiment allows the fit of the exoskeleton system 100 to be quickly modified by the user to account for the changes or a desire to change fit of the exoskeleton system 100. For example, user-adjustable modifications may allow the user to remain in control and deliver on a fit that they prefer or that is desirable for the task at hand, or for other reasons. One embodiment provides the user with a first set of granular adjustments that are readily accessible that can be adjusted throughout a specific mission (e.g., dials on a leg actuator unit 110 that are accessible to the hands of a user wearing the leg actuator unit 110 that can be easily manipulated while the user is wearing the leg actuator unit 110) and second set of less-accessible adjustments that can be used to account for coarse modifications to the fit of the exoskeleton system 100 (e.g., strap cinches, or the like, that may be more difficult to manipulate based on location and/or configuration).

Another embodiment incorporates active actuation into system fit, which can be used to maintain a desired fit of the exoskeleton system 100 on the user 101. For example, in some embodiments, various one or more portions of one or more actuation units 110 that are associated with fit of the one or more actuation units 110 to the body of the user can be actuated by the exoskeleton device 510 (e.g., motors that can tighten and/or loosen one or more couplers 150, or other portions of a leg actuation unit 110). In such an embodiment, sensors 513 can determine a pressure, tension, or the like of straps (e.g., couplers 150) and the exoskeleton device 510 can obtain such data, determine whether the fit of one or more actuation units 110 is within fit parameters, and if not, adjust the fit of the one or more actuation units 110 by actuating one or more fit components of the one or more actuation units 110 to tighten and/or loosen such fit components to bring the fit of the one or more actuation units 110 within the fit parameters.

In some embodiments, fit parameters can be determined based on various suitable factors such as a determined or indicated task, mission or maneuver; data from sensors indicating performance of one or more actuation units 110; user input regarding fit or comfort of one or more actuation units 110, and the like. In various embodiments, the exoskeleton system 100 can identify specific straps, couplings or the like, that are too loose, too tight, or otherwise inappropriately fit. Modification of the fit of one or more actuation units 110 can be done automatically continuously or at an interval (e.g., by the exoskeleton device 510) or based at least in part on user input via an interface 515.

While specific embodiments of couplers 150 are illustrated herein, in further embodiments, such components discussed herein can be operably replaced by an alternative structure to produce the same functionality. For example, while straps, buckles, padding and the like are shown in various examples, further embodiments can include couplers 150 of various suitable types and with various suitable elements. For example, some embodiments can include Velcro hook-and-loop straps, or the like.

FIGS. 1-3 and 6-10 illustrate examples of an exoskeleton system 100 where the joint 125 is disposed laterally and adjacent to the knee 103 with a rotational axis of the joint 125 being disposed parallel to a rotational axis of the knee 103. In some embodiments, the rotational axis of the joint 125 can be coincident with the rotational axis of the knee 103. In some embodiments, a joint can be disposed on the anterior of the knee 103, posterior of the knee 103, inside of the knee 103, or the like.

In various embodiments, the joint structure 125 can constrain the bellows actuator 130 such that force created by actuator fluid pressure within the bellows actuator 130 can be directed about an instantaneous center (which may or may not be fixed in space). In some cases of a revolute or rotary joint, or a body sliding on a curved surface, this instantaneous center can coincide with the instantaneous center of rotation of the joint 125 or a curved surface. Forces created by a leg actuator unit 110 about a rotary joint 125 can be used to apply a moment about an instantaneous center as well as still be used to apply a directed force. In some cases of a prismatic or linear joint (e.g., a slide on a rail, or the like), the instantaneous center can be kinematically considered to be located at infinity, in which case the force directed about this infinite instantaneous center can be considered as a force directed along the axis of motion of the prismatic joint. In various embodiments, it can be sufficient for a rotary joint 125 to be constructed from a mechanical pivot mechanism. In such an embodiment, the joint 125 can have a fixed center of rotation that can be easy to define, and the bellows actuator 130 can move relative to the joint 125. In a further embodiment, it can be beneficial for the joint 125 to comprise a complex linkage that does not have a single fixed center of rotation. In yet another embodiment, the joint 125 can comprise a flexure design that does not have a fixed joint pivot. In still further embodiments, the joint 125 can comprise a structure, such as a human joint, robotic joint, or the like.

In various embodiments, leg actuator unit 110 (e.g., comprising bellows actuator 130, joint structure 125, and the like) can be integrated into a system to use the generated directed force of the leg actuator unit 110 to accomplish various tasks. In some examples, a leg actuator unit 110 can have one or more unique benefits when the leg actuator unit 110 is configured to assist the human body or is included into a powered exoskeleton system 100. In an example embodiment, the leg actuator unit 110 can be configured to assist the motion of a human user about the user's knee joint 103. To do so, in some examples, the instantaneous center of the leg actuator unit 110 can be designed to coincide or nearly coincide with the instantaneous center of rotation of the knee 103 of a user 101. In one example configuration, the leg actuator unit 110 can be positioned lateral to the knee joint 103 as shown in FIGS. 1-3 and 6-10. In various examples, the human knee joint 103 can function as (e.g., in addition to or in place of) the joint 125 of the leg actuator unit 110.

For clarity, example embodiments discussed herein should not be viewed as a limitation of the potential applications of the leg actuator unit 110 described within this disclosure. The leg actuator unit 110 can be used on other joints of the body including but not limited to one or more elbow, one or more hip, one or more finger, one or more ankle, spine, or neck. In some embodiments, the leg actuator unit 110 can be used in applications that are not on the human body such as in robotics, for general purpose actuation, animal exoskeletons, or the like.

Also, embodiments can be used for or adapted for various suitable applications such as tactical, medical, or labor applications, and the like. Examples of such applications can be found in U.S. patent application Ser. No. 15/823,523, filed Nov. 27, 2017 entitled “PNEUMATIC EXOMUSCLE SYSTEM AND METHOD” with attorney docket number 0110496-002US1 and U.S. patent application Ser. No. 15/953,296, filed Apr. 13, 2018 entitled “LEG EXOSKELETON SYSTEM AND METHOD” with attorney docket number 0110496-004US0, which are incorporated herein by reference.

Some embodiments can apply a configuration of a leg actuator unit 110 as described herein for linear actuation applications. In an example embodiment, the bellows actuator 130 can comprise a two-layer impermeable/inextensible construction, and one end of one or more constraining ribs can be fixed to the bellows actuator 130 at predetermined positions. The joint structure 125 in various embodiments can be configured as a series of slides on a pair of linear guide rails, where the remaining end of one or more constraining ribs is connected to a slide. The motion and force of the fluidic actuator can therefore be constrained and directed along the linear rail.

FIG. 5 is a block diagram of an example embodiment of an exoskeleton system 100 that includes an exoskeleton device 510 that is operably connected to a pneumatic system 520. While a pneumatic system 520 is used in the example of FIG. 5, further embodiments can include any suitable fluidic system or a pneumatic system 520 can be absent in some embodiments, such as where an exoskeleton system 100 is actuated by electric motors, or the like.

The exoskeleton device 510 in this example comprises a processor 511, a memory 512, one or more sensors 513 a communication unit 514, a user interface 515 and a power source 516. A plurality of actuators 130 are operably coupled to the pneumatic system 520 via respective pneumatic lines 145. The plurality of actuators 130 include a pair of knee-actuators 130L and 130R that are positioned on the right and left side of a body 100. For example, as discussed above, the example exoskeleton system 100 shown in FIG. 5 can comprise a left and right leg actuator unit 110L, 110R on respective sides of the body 101 as shown in FIGS. 1 and 2 with one or both of the exoskeleton device 510 and pneumatic system 520, or one or more components thereof, stored within or about a backpack 155 (see FIG. 1) or otherwise mounted, worn or held by a user 101.

Accordingly, in various embodiments, the exoskeleton system 100 can be a completely mobile and self-contained system that is configured to be powered and operate for an extended period of time without an external power source during various user activities. The size, weight and configuration of the actuator unit(s) 110, exoskeleton device 510 and pneumatic system 520 can therefore be configured in various embodiments for such mobile and self-contained operation.

In various embodiments, the example system 100 can be configured to move and/or enhance movement of the user 101 wearing the exoskeleton system 100. For example, the exoskeleton device 510 can provide instructions to the pneumatic system 520, which can selectively inflate and/or deflate the bellows actuators 130 via pneumatic lines 145. Such selective inflation and/or deflation of the bellows actuators 130 can move and/or support one or both legs 102 to generate and/or augment body motions such as walking, running, jumping, climbing, lifting, throwing, squatting, skiing or the like.

In some cases, the exoskeleton system 100 can be designed to support multiple configurations in a modular configuration. For example, one embodiment is a modular configuration that is designed to operate in either a single knee configuration or in a double knee configuration as a function of how many of the actuator units 110 are donned by the user 101. For example, the exoskeleton device 510 can determine how many actuator units 110 are coupled to the pneumatic system 520 and/or exoskeleton device 510 (e.g., on or two actuator units 110) and the exoskeleton device 510 can change operating capabilities based on the number of actuator units 110 detected.

In further embodiments, the pneumatic system 520 can be manually controlled, configured to apply a constant pressure, or operated in any other suitable manner. In some embodiments, such movements can be controlled and/or programmed by the user 101 that is wearing the exoskeleton system 100 or by another person. In some embodiments, the exoskeleton system 100 can be controlled by movement of the user 101. For example, the exoskeleton device 510 can sense that the user is walking and carrying a load and can provide a powered assist to the user via the actuators 130 to reduce the exertion associated with the load and walking. Similarly, where a user 101 wears the exoskeleton system 100, the exoskeleton system 100 can sense movements of the user 101 and can provide a powered assist to the user via the actuators 130 to enhance or provide an assist to the user while skiing.

Accordingly, in various embodiments, the exoskeleton system 130 can react automatically without direct user interaction. In further embodiments, movements can be controlled in real-time by user interface 515 such as a controller, joystick, voice control or thought control. Additionally, some movements can be pre-preprogrammed and selectively triggered (e.g., walk forward, sit, crouch) instead of being completely controlled. In some embodiments, movements can be controlled by generalized instructions (e.g. walk from point A to point B, pick up box from shelf A and move to shelf B).

The user interface 515 can allow the user 101 to control various aspects of the exoskeleton system 100 including powering the exoskeleton system 100 on and off; controlling movements of the exoskeleton system 100; configuring settings of the exoskeleton system 100, and the like. The user interface 515 can include various suitable input elements such as a touch screen, one or more buttons, audio input, and the like. The user interface 515 can be located in various suitable locations about the exoskeleton system 100. For example, in one embodiment, the user interface 515 can be disposed on a strap of a backpack 155, or the like. In some embodiments, the user interface can be defined by a user device such as smartphone, smart-watch, wearable device, or the like.

In various embodiments, the power source 516 can be a mobile power source that provides the operational power for the exoskeleton system 100. In one preferred embodiment, the power pack unit contains some or all of the pneumatic system 520 (e.g., a compressor) and/or power source (e.g., batteries) required for the continued operation of pneumatic actuation of the leg actuator units 110. The contents of such a power pack unit can be correlated to the specific actuation approach configured to be used in the specific embodiment. In some embodiments, the power pack unit will only contain batteries which can be the case in an electromechanically actuated system or a system where the pneumatic system 520 and power source 516 are separate. Various embodiments of a power pack unit can include but are not limited to a combination of the one or more of the following items: pneumatic compressor, batteries, stored high-pressure pneumatic chamber, hydraulic pump, pneumatic safety components, electric motor, electric motor drivers, microprocessor, and the like. Accordingly, various embodiments of a power pack unit can include one or more of elements of the exoskeleton device 510 and/or pneumatic system 520.

Such components can be configured on the body of a user 101 in a variety of suitable ways. One preferred embodiment is the inclusion of a power pack unit in a torso-worn pack that is not operably coupled to the leg actuator units 110 in any manner that transmits substantial mechanical forces to the leg actuator units 110. Another embodiment includes the integration of the power pack unit, or components thereof, into the leg actuator units 110 themselves. Various embodiments can include but are not limited to the following configurations: torso-mounted in a backpack, torso-mounted in a messenger bag, hip-mounted bag, mounted to the leg, integrated into the brace component, and the like. Further embodiments can separate the components of the power pack unit and disperse them into various configurations on the user 101. Such an embodiment may configure a pneumatic compressor on the torso of the user 101 and then integrate the batteries into the leg actuator units 110 of the exoskeleton system 100.

One aspect of the power supply 516 in various embodiments is that it must be connected to the brace component in such a manner as to pass the operable system power to the brace for operation. One preferred embodiment is the use of electrical cables to connect the power supply 516 and the leg actuator units 110. Other embodiments can use electrical cables and a pneumatic line 145 to deliver electrical power and pneumatic power to the leg actuator units 110. Various embodiments can include but are not limited to any configuration of the following connections: pneumatic hosing, hydraulic hosing, electrical cables, wireless communication, wireless power transfer, and the like.

In some embodiments, it can be desirable to include secondary features that extend the capabilities of a cable connection (e.g., pneumatic lines 145 and/or power lines) between the leg actuator units 110 and the power supply 516 and/or pneumatic system 520. One preferred embodiment includes retractable cables that are configured to have a small mechanical retention force to maintain cables that are pulled tight against the user with reduced slack remaining in the cable. Various embodiments can include, but are not limited to a combination of the following secondary features: retractable cables, a single cable including both fluidic and electrical power, magnetically-connected electrical cables, mechanical quick releases, breakaway connections designed to release at a specified pull force, integration into mechanical retention features on the user's clothing, and the like. Yet another embodiment can include routing the cables in such a way as to minimize geometric differences between the user 101 and the cable lengths. One such embodiment in a dual knee configuration with a torso power supply can be routing the cables along the user's lower torso to connect the right side of a power supply bag with the left knee of the user. Such a routing can allow the geometric differences in length throughout the user's normal range of motion.

One specific additional feature that can be a concern in some embodiments is the need for proper heat management of the exoskeleton system 100. As a result, there are a variety of features that can be integrated specifically for the benefit of controlling heat. One preferred embodiment integrates exposed heat sinks to the environment that allow elements of the exoskeleton device 510 and/or pneumatic system 520 to dispel heat directly to the environment through unforced cooling using ambient airflow. Another embodiment directs the ambient air through internal air channels in a backpack 155 or other housing to allow for internal cooling. Yet another embodiment can extend upon this capability by introducing scoops on a backpack 155 or other housing in an effort to allow air flow through the internal channels. Various embodiments can include but are not limited to the following: exposed heat sinks that are directly connected to a high heat component; a water-cooled or fluid-cooled heat management system; forced air cooling through the introduction of a powered fan or blower; external shielded heat sinks to protect them from direct contact by a user, and the like.

In some cases, it may be beneficial to integrate additional features into the structure of the backpack 155 or other housing to provide additional features to the exoskeleton system 100. One preferred embodiment is the integration of mechanical attachments to support storage of the leg actuator units 110 along with the exoskeleton device 510 and/or pneumatic system 520 in a small package. Such an embodiment can include a deployable pouch that can secure the leg actuator units 110 against the backpack 155 along with mechanical clasps that hold the upper or lower arms 115, 120 of the actuator units 110 to the backpack 155. Another embodiment is the inclusion of storage capacity into the backpack 155 so the user 101 can hold additional items such as a water bottle, food, personal electronics, and other personal items. Various embodiments can include but are not limited to other additional features such as the following: a warming pocket which is heated by hot airflow from the exoskeleton device 510 and/or pneumatic system 520; air scoops to encourage additional airflow internal to the backpack 155; strapping to provide a closer fit of the backpack 155 on the user, waterproof storage, temperature-regulated storage, and the like.

In a modular configuration, it may be required in some embodiments that the exoskeleton device 510 and/or pneumatic system 520 can be configured to support the power, fluidic, sensing and control requirements and capabilities of various potential configurations of the exoskeleton system. One preferred embodiment can include an exoskeleton device 510 and/or pneumatic system 520 that can be tasked with powering a dual knee configuration or a single knee configuration (i.e., with one or two leg actuator units 110 on the user 101). Such an exoskeleton system 100 can support the requirements of both configurations and then appropriately configure power, fluidic, sensing and control based on a determination or indication of a desired operating configuration. Various embodiments exist to support an array of potential modular system configurations, such as multiple batteries, and the like.

In various embodiments, the exoskeleton device 100 can be operable to perform methods or portions of methods described in more detail below or in related applications incorporated herein by reference. For example, the memory 512 can include non-transitory computer readable instructions (e.g., software), which if executed by the processor 511, can cause the exoskeleton system 100 to perform methods or portions of methods described herein or in related applications incorporated herein by reference.

This software can embody various methods that interpret signals from the sensors 513 or other sources to determine how to best operate the exoskeleton system 100 to provide the desired benefit to the user. The specific embodiments described below should not be used to imply a limit on the sensors 513 that can be applied to such an exoskeleton system 100 or the source of sensor data. While some example embodiments can require specific information to guide decisions, it does not create an explicit set of sensors 513 that an exoskeleton system 100 will require and further embodiments can include various suitable sets of sensors 513. Additionally, sensors 513 can be located at various suitable locations on an exoskeleton system 100 including as part of an exoskeleton device 510, pneumatic system 520, one or more fluidic actuator 130, or the like. Accordingly, the example illustration of FIG. 5 should not be construed to imply that sensors 513 are exclusively disposed at or part of an exoskeleton device 510 and such an illustration is merely provided for purposes of simplicity and clarity.

One aspect of control software can be the operational control of leg actuator units 110, exoskeleton device 510 and pneumatic system 520 to provide the desired response. There can be various suitable responsibilities of the operational control software. For example, as discussed in more detail below, one can be low-level control which can be responsible for developing baseline feedback for operation of the leg actuator units 110, exoskeleton device 510 and pneumatic system 520. Another can be intent recognition which can be responsible for identifying the intended maneuvers of the user 101 based on data from the sensors 513 and causing the exoskeleton system 100 to operate based on one or more identified intended maneuvers. A further example can include reference generation, which can include selecting the desired torques the exoskeleton system 100 should generate to best assist the user 101. It should be noted that this example architecture for delineating the responsibilities of the operational control software is merely for descriptive purposes and in no way limits the wide variety of software approaches that can be deployed on further embodiments of an exoskeleton system 100.

One method implemented by control software can be for the low-level control and communication of the exoskeleton system 100. This can be accomplished via a variety of methods as required by the specific joint and need of the user. In a preferred embodiment, the operational control is configured to provide a desired torque by the leg actuator unit 110 at the user's joint. In such a case, the exoskeleton system 100 can create low-level feedback to achieve a desired joint torque by the leg actuator units 110 as a function of feedback from the sensors 513 of the exoskeleton system 100. For example, such a method can include obtaining sensor data from one or more sensors 513, determining whether a change in torque by the leg actuator unit 110 is necessary, and if so, causing the pneumatic system 520 to change the fluid state of the leg actuator unit 110 to achieve a target joint torque by the leg actuator unit 110. Various embodiments can include, but are not limited to, the following: current feedback; recorded behavior playback; position-based feedback; velocity-based feedback; feedforward responses; volume feedback which controls a fluidic system 520 to inject a desired volume of fluid into an actuator 130, and the like.

Another method implemented by operational control software can be for intent recognition of the user's intended behaviors. This portion of the operational control software, in some embodiments, can indicate any array of allowable behaviors that the system 100 is configured to account for. In one preferred embodiment, the operational control software is configured to identify two specific states: Walking, and Not Walking. In such an embodiment, to complete intent recognition, the exoskeleton system 100 can use user input and/or sensor readings to identify when it is safe, desirable or appropriate to provide assistive actions for walking. For example, in some embodiments, intent recognition can be based on input received via the user interface 515, which can include an input for Walking, and Not Walking. Accordingly, in some examples, the use interface can be configured for a binary input consisting of Walking, and Not Walking.

In some embodiments, a method of intent recognition can include the exoskeleton device 510 obtaining data from the sensors 513 and determining, based at least in part of the obtained data, whether the data corresponds to a user state of Walking, and Not Walking. Where a change in state has been identified, the exoskeleton system 100 can be re-configured to operate in the current state. For example, the exoskeleton device 510 can determine that the user 101 is in a Not Walking state such as sitting and can configure the exoskeleton system 100 to operate in a Not Walking configuration. For example, such a Not Walking configuration can, compared to a Walking configuration, provide for a wider range of motion; provide no torque or minimal torque to the leg actuation units 110; save power and fluid by minimizing processing and fluidic operations; cause the system to be alert for supporting a wider variety of non-skiing motion, and the like.

The exoskeleton device 510 can monitor the activity of the user 101 and can determine that the user is walking or is about to walk (e.g., based on sensor data and/or user input), and can then configure the exoskeleton system 100 to operate in a Walking configuration. For example, such a Walking configuration, compared to a Not Walking configuration, can allow for a more limited range of motion that would be present during skiing (as opposed to motions during non-walking); provide for high or maximum performance by increasing the processing and fluidic response of the exoskeleton system 100 to support skiing; and the like. When the user 101 finishes a walking session, is identified as resting, or the like, the exoskeleton system 100 can determine that the user is no longer walking (e.g., based on sensor data and/or user input) and can then configure the exoskeleton system 100 to operate in the Not Walking configuration.

In some embodiments, there can be a plurality of Walking states, or Walking sub-states that can be determined by the exoskeleton system 100, including hard walking, moderate walking, light walking, downhill, uphill, jumping, recreational, sport, running, and the like (e.g., based on sensor data and/or user input). Such states can be based on the difficulty of the walking, ability of the user, terrain, weather conditions, elevation, angle of the walking surface, desired performance level, power-saving, and the like. Accordingly, in various embodiments, the exoskeleton system 100 can adapt for various specific types of walking or movement based on a wide variety of factors.

Another method implemented by operational control software can be the development of desired referenced behaviors for the specific joints providing assistance. This portion of the control software can tie together identified maneuvers with the level control. For example, when the exoskeleton system 100 identifies an intended user maneuver, the software can generate reference behaviors that define the torques, or positions desired by the actuators 130 in the leg actuation units 110. In one embodiment, the operational control software generates references to make the leg actuation units 110 simulate a mechanical spring at the knee 103 via the configuration actuator 130. The operational control software can generate torque references at the knee joints that are a linear function of the knee joint angle. In another embodiment, the operational control software generates a volume reference to provide a constant standard volume of air into a pneumatic actuator 130. This can allow the pneumatic actuator 130 to operate like a mechanical spring by maintaining the constant volume of air in the actuator 130 regardless of the knee angle, which can be identified through feedback from one or more sensors 513.

In another embodiment, a method implemented by the operational control software can include evaluating the balance of the user 101 while walking, moving, standing, or running and directing torque in such a way to encourage the user 101 to remain balanced by directing knee assistance to the leg 102 that is on the outside of the user's current balance profile. Accordingly, a method of operating an exoskeleton system 100 can include the exoskeleton device 510 obtaining sensor data from the sensors 510 indicating a balance profile of a user 101 based on the configuration of left and right leg actuation units 110L, 110R and/or environmental sensors such as position sensors, accelerometers, and the like. The method can further include determining a balance profile based on the obtained data, including an outside and inside leg, and then increasing torque to the actuation unit 110 associated with the leg 102 identified as the outside leg.

Various embodiments can use but are not limited to kinematic estimates of posture, joint kinetic profile estimates, as well as observed estimates of body pose. Various other embodiments exist for methods of coordinating two legs 102 to generate torques including but not limited to guiding torque to the most bent leg; guiding torque based on the mean amount of knee angle across both legs; scaling the torque as a function of speed or acceleration; and the like. It should also be noted that yet another embodiment can include a combination of various individual reference generation methods in a variety of matters which include but are not limited to a linear combination, a maneuver specific combination, or a non-linear combination.

In another embodiment, an operational control method can blend two primary reference generation techniques: one reference focused on static assistance and one reference focused on leading the user 101 into their upcoming behavior. In some examples, the user 101 can select how much predictive assistance is desired while using the exoskeleton system 100. For example, by a user 101 indicating a large amount of predictive assistance, the exoskeleton system 100 can be configured to be very responsive and may be well configured for a skilled operator on a challenging terrain. The user 101 could also indicate a desire for a very low amount of predictive assistance, which can result in slower system performance, which may be better tailored towards a learning user or less challenging terrain.

Various embodiments can incorporate user intent in a variety of manners and the example embodiments presented above should not be interpreted as limiting in any way. For example, method of determining and operating an exoskeleton system 100 can include systems and method of U.S. patent application Ser. No. 15/887,866, filed Feb. 2, 2018 entitled “SYSTEM AND METHOD FOR USER INTENT RECOGNITION,” having attorney docket number 0110496-003US0, which is incorporated herein by reference. Also, various embodiments can use user intent in a variety of manners including as a continuous unit, or as a discrete setting with only a few indicated values.

At times it can be beneficial for operational control software to manipulate its control to account for a secondary or additional objective in order to maximize device performance or user experience. In one embodiment, the exoskeleton system 100 can provide an elevation-aware control over a central compressor or other components of a pneumatic system 520 to account for the changing density of air at different elevations. For example, operational control software can identify that the system is operating at a higher elevation based on data from sensors 513, or the like, and provide more current to the compressor in order to maintain electrical power consumed by the compressor. Accordingly, a method of operating a pneumatic exoskeleton system 100 can include obtaining data indicating air density where the pneumatic exoskeleton system 100 is operating (e.g., elevation data), determining optimal operating parameters of the pneumatic system 520 based on the obtained data, and configuring operation based on the determined optimal operating parameters. In further embodiments, operation of a pneumatic exoskeleton system 100 such as operating volumes can be tuned based on environmental temperature, which may affect air volumes.

In another embodiment, the exoskeleton system 100 can monitor the ambient audible noise levels and vary the control behavior of the exoskeleton system 100 to reduce the noise profile of the system. For example, when a user 101 is in a quiet public place or quietly enjoying a location alone or with others, noise associated with actuation of the leg actuation units 110 can be undesirable (e.g., noise of running a compressor or inflating or deflating actuators 130). Accordingly, in some embodiments, the sensors 513 can include a microphone that detects ambient noise levels and can configure the exoskeleton system 100 to operate in a quiet mode when ambient noise volume is below a certain threshold. Such a quiet mode can configure elements of a pneumatic system 520 or actuators 130 to operate more quietly, or can delay or reduce frequency of noise made by such elements.

In the case of a modular system, it can be desirable in various embodiments for operational control software to operate differently based on the number of leg actuation units 110 operational within the exoskeleton system 100. For example, in some embodiments, a modular dual-knee exoskeleton system 100 (see e.g., FIGS. 1 and 2) can also operate in a single knee configuration where only one of two leg actuation units 110 are being worn by a user 101 (see e.g., FIGS. 3 and 4) and the exoskeleton system 100 can generate references differently when in a two-leg configuration compared to a single leg configuration. Such an embodiment can use a coordinated control approach to generate references where the exoskeleton system 100 is using inputs from both leg actuation units 110 to determine the desired operation. However in a single-leg configuration, the available sensor information may have changed, so in various embodiments the exoskeleton system 100 can implement a different control method. In various embodiments this can be done to maximize the performance of the exoskeleton system 100 for the given configuration or account for differences in available sensor information based on there being one or two leg actuation units 110 operating in the exoskeleton system 100.

Accordingly, a method of operating an exoskeleton system 100 can include a startup sequence where a determination is made by the exoskeleton device 510 whether one or two leg actuation units 110 are operating in the exoskeleton system 100; determining a control method based on the number of actuation units 110 that are operating in the exoskeleton system 100; and implementing and operating the exoskeleton system 100 with the selected control method. A further method operating an exoskeleton system 100 can include monitoring by the exoskeleton device 510 of actuation units 110 that are operating in the exoskeleton system 100, determining a change in the number of actuation units 110 operating in the exoskeleton system 100, and then determining and changing the control method based on the new number of actuation units 110 that are operating in the exoskeleton system 100.

For example, the exoskeleton system 100 can be operating with two actuation units 110 and with a first control method. The user 101 can disengage one of the actuation units 110, and the exoskeleton device 510 can identify the loss of one of the actuation units 110 and the exoskeleton device 510 can determine and implement a new second control method to accommodate loss of one of the actuation units 110. In some examples, adapting to the number of active actuation units 110 can be beneficial where one of the actuation units 110 is damaged or disconnected during use and the exoskeleton system 100 is able to adapt automatically so the user 101 can still continue working or moving uninterrupted despite the exoskeleton system 100 only having a single active actuation unit 110.

In various embodiments, operational control software can adapt a control method where user needs are different between individual actuation units 110 or legs 102. In such an embodiment, it can be beneficial for the exoskeleton system 100 to change the torque references generated in each actuation unit 110 to tailor the experience for the user 101. One example is of a dual knee exoskeleton system 100 (see e.g., FIG. 1) where a user 101 has significant weakness issues in a single leg 102, but only minor weakness issues in the other leg 102. In this example, the exoskeleton system 100 can be configured to scale down the output torques on the less-affected limb compared to the more-affected limb to best meet the needs of the user 101.

Such a configuration based on differential limb strength can be done automatically by the exoskeleton system 100 and/or can be configured via a user interface 516, or the like. For example, in some embodiments, the user 101 can perform a calibration test while using the exoskeleton system 100, which can test relative strength or weakness in the legs 102 of the user 101 and configure the exoskeleton system 100 based on identified strength or weakness in the legs 102. Such a test can identify general strength or weakness of legs 102 or can identify strength or weakness of specific muscles or muscle groups such as the quadriceps, calves, hamstrings, gluteus, gastrocnemius; femoris, sartorius, soleus, and the like.

Another aspect of a method for operating an exoskeleton system 100 can include control software that monitors the exoskeleton system 100. A monitoring aspect of such software can, in some examples, focus on monitoring the state of the exoskeleton system 100 and the user 101 throughout normal operation in an effort to provide the exoskeleton system 100 with situational awareness and understanding of sensor information in order to drive user understanding and device performance. One aspect of such monitoring software can be to monitor the state of the exoskeleton system 100 in order to provide device understanding to achieve a desired performance capability. A portion of this can be the development of a system body pose estimate. In one embodiment, the exoskeleton device 510 uses the onboard sensors 513 to develop a real-time understanding of the user's pose. In other words, data from sensors 513 can be used to determine the configuration of the actuation units 110, which along with other sensor data can in turn be used to infer a user pose or body configuration estimate of the user 101 wearing the actuation units 110.

At times, and in some embodiments, it can be unrealistic or impossible for the exoskeleton system 100 to directly sense all important aspects of the system pose due to the sensing modalities not existing or their inability to be practically integrated into the hardware. As a result, the exoskeleton system 100 in some examples can rely on a fused understanding of the sensor information around an underlying model of the user's body and the exoskeleton system 100 the user is wearing. In one embodiment of a dual leg knee assistance exoskeleton system 100, the exoskeleton device 510 can use an underlying model of the user's lower extremity and torso body segments to enforce a relational constraint between the otherwise disconnected sensors 513. Such a model can allow the exoskeleton system 100 to understand the constrained motion of the two legs 102 in that they are mechanically connected through the user's kinematic chain created by the body. This approach can be used to ensure that the estimates for knee orientation are properly constrained and biomechanically valid. In various embodiments, the exoskeleton system 100 can include sensors 513 embedded in the exoskeleton device 510 and/or pneumatic system 520 to provide a fuller picture of the system posture. In yet another embodiment, the exoskeleton system 100 can include logical constraints that are unique to the application in an effort to provide additional constraints on the operation of the pose estimation. This can be desirable, in some embodiments, in conditions where ground truth information is unavailable such as highly dynamic actions, where the exoskeleton system 100 is denied an external GPS signal, or the earth's magnetic field is distorted.

In some embodiments, changes in configuration of the exoskeleton system 100 based location and/or location attributes can be performed automatically and/or with input from the user 101. For example, in some embodiments, the exoskeleton system 100 can provide one or more suggestions for a change in configuration based on location and/or location attributes and the user 101 can choose to accept such suggestions. In further embodiments, some or all configurations of the exoskeleton system 100 based location and/or location attributes can occur automatically without user interaction.

Various embodiments can include the collection and storage of data from the exoskeleton system 100 throughout operation. In one embodiment, this can include the live streaming of the data collected on the exoskeleton device 510 to a cloud storage location via the communication unit(s) 514 through an available wireless communication protocol or storage of such data on the memory 512 of the exoskeleton device 510, which may then be uploaded to another location via the communication unit(s) 514. For example, when the exoskeleton system 100 obtains a network connection, recorded data can be uploaded to the cloud at a communication rate that is supported by the available data connection. Various embodiments can include variations of this, but the use of monitoring software to collect and store data about the exoskeleton system 100 locally and/or remotely for retrieval at a later time for an exoskeleton system 100 such as this can be included in various embodiments.

In some embodiments, once such data has been recorded, it can be desirable to use the data for a variety of different applications. One such application can be the use of the data to develop further oversight functions on the exoskeleton system 100 in an effort to identify device system issues that are of note. One embodiment can be the use of the data to identify a specific exoskeleton system 100 or leg actuator unit 110 among a plurality, whose performance has varied significantly over a variety of uses. Another use of the data can be to provide it back to the user 101 to gain a better understanding of how they ski. One embodiment of this can be providing the data back to the user 101 through a mobile application that can allow the user 101 to review their use on a mobile device. Yet another use of such device data can be to synchronize playback of data with an external data stream to provide additional context. One embodiment is a system that incorporates the GPS data from a companion smartphone with the data stored natively on the device. Another embodiment can include the time synchronization of recorded video with the data stored that was obtained from the device 100. Various embodiments can use these methods for immediate use of data by the user to evaluate their own performance, for later retrieval by the user to understand behavior from the past, for users to compare with other users in-person or through an online profile, by developers to further the development of the system, and the like.

Another aspect of a method of operating an exoskeleton system 100 can include monitoring software configured for identifying user-specific traits. For example, the exoskeleton system 100 can provide an awareness of how a specific skier 101 operates in the exoskeleton system 100 and over time can develop a profile of the user's specific traits in an effort to maximize device performance for that user. One embodiment can include the exoskeleton system 100 identifying a user-specific use type in an effort to identify the use style or skill level of the specific user. Through an evaluation of the user form and stability during various actions (e.g., via analysis of data obtained from the sensors 513 or the like), the exoskeleton device 510 in some examples can identify if the user is highly skilled, novice, or beginner. This understanding of skill level or style can allow the exoskeleton system 100 to better tailor control references to the specific user.

In further embodiments, the exoskeleton system 100 can also use individualized information about a given user to build a profile of the user's biomechanic response to the exoskeleton system 100. One embodiment can include the exoskeleton system 100 collecting data regarding the user to develop an estimate of the individual user's knee strain in an effort to assist the user with understanding the burden the user has placed on his legs 102 throughout use. This can allow the exoskeleton system 100 to alert a user if the user has reached a historically significant amount of knee strain to alert the user that he may want to stop to spare himself potential pain or discomfort.

Another embodiment of individualized biomechanic response can be the system collecting data regarding the user to develop an individualized system model for the specific user. In such an embodiment the individualized model can be developed through a system ID (identification) method that evaluates the system performance with an underlying system model and can identify the best model parameters to fit the specific user. The system ID in such an embodiment can operate to estimate segment lengths and masses (e.g., of legs 102 or portions of the legs 102) to better define a dynamic user model. In another embodiment, these individualized model parameters can be used to deliver user specific control responses as a function of the user's specific masses and segment lengths. In some examples of a dynamic model, this can help significantly with the device's ability to account for dynamic forces during highly challenging activities.

In various embodiments, the exoskeleton system 100 can provide for various types of user interaction. For example, such interaction can include input from the user 101 as needed into the exoskeleton system 100 and the exoskeleton system 100 providing feedback to the user 101 to indicate changes in operation of the exoskeleton system 100, status of the exoskeleton system 100, and the like. As discussed herein, user input and/or output to the user can be provided via one or more user interface 515 of the exoskeleton device 510 or can include various other interfaces or devices such as a smartphone user device. Such one or more user interfaces 515 or devices can be located in various suitable locations such as on a backpack 155 (see e.g., FIG. 1), the pneumatic system 520, leg actuation units 110, or the like.

The exoskeleton system 100 can be configured to obtain intent from the user 101. For example, this can be accomplished through a variety of input devices that are either integrated directly with the other components of the exoskeleton system 100 (e.g., one or more user interface 515), or external and operably connected with the exoskeleton system 100 (e.g., a smartphone, wearable device, remote server, or the like). In one embodiment, a user interface 515 can comprise a button that is integrated directly into one or both of the leg actuation units 110 of the exoskeleton system 100. This single button can allow the user 101 to indicate a variety of inputs. In another embodiment, a user interface 515 can be configured to be provided through a torso-mounted lapel input device that is integrated with the exoskeleton device 510 and/or pneumatic system 520 of the exoskeleton system 100. In one example, such a user interface 515 can comprise a button that has a dedicated enable and disable functionality; a selection indicator dedicated to the user's desired power level (e.g., an amount or range of force applied by the leg actuator units 110); and a selector switch that can be dedicated to the amount of predictive intent to integrate into the control of the exoskeleton system 100. Such an embodiment of a user interface 515 can use a series of functionally locked buttons to provide the user 101 with a set of understood indicators that may be required for normal operation in some examples. Yet another embodiment can include a mobile device that is connected to the exoskeleton system 100 via a Bluetooth connection or other suitable wired or wireless connection. Use of a mobile device or smartphone as a user interface 515 can allow the user a far greater amount of input to the device due to the flexibility of the input method. Various embodiments can use the options listed above or combinations and variants thereof, but are in no way limited to the explicitly stated combinations of input methods and items.

The one or more user interface 515 can provide information to the user 101 to allow the user to appropriately use and operate the exoskeleton system 100. Such feedback can be in a variety of visual, haptic and/or audio methods including, but not limited to, feedback mechanisms integrated directly on one or both of the actuation units 110; feedback through operation of the actuation units 110; feedback through external items not integrated with the exoskeleton system 100 (e.g., a mobile device); and the like. Some embodiments can include integration of feedback lights in the actuation units 110, of the exoskeleton system 100. In one such embodiment, five multi-color lights are integrated into the knee joint 125 or other suitable location such that the user 101 can see the lights. These lights can be used to provide feedback of system errors, device power, successful operation of the device, and the like. In another embodiment, the exoskeleton system 100 can provide controlled feedback to the user to indicate specific pieces of information. In such embodiments, the exoskeleton system 100 can pulse the joint torque on one or both of the leg actuation units 110 to the maximum allowed torque when the user changes the maximum allowable user-desired torque, which can provide a haptic indicator of the torque settings. Another embodiment can use an external device such as a mobile device where the exoskeleton system 100 can provide alert notifications for device information such as operational errors, setting status, power status, and the like. Types of feedback can include, but are not limited to, lights, sounds, vibrations, notifications, and operational forces integrated in a variety of locations that the user 101 may be expected to interact with including the actuation units 110, pneumatic system 520, backpack 155, mobile devices, or other suitable methods of interactions such as a web interface, SMS text or email.

The communication unit 514 can include hardware and/or software that allows the exoskeleton system 100 to communicate with other devices, including a user device, a classification server, other exoskeleton systems 100, or the like, directly or via a network. For example, the exoskeleton system 100 can be configured to connect with a user device, which can be used to control the exoskeleton system 100, receive performance data from the exoskeleton system 100, facilitate updates to the exoskeleton system, and the like. Such communication can be wired and/or wireless communication.

In some embodiments, the sensors 513 can include any suitable type of sensor, and the sensors 513 can be located at a central location or can be distributed about the exoskeleton system 100. For example, in some embodiments, the exoskeleton system 100 can comprise a plurality of accelerometers, force sensors, position sensors, and the like, at various suitable positions, including at the arms 115, 120, joint 125, actuators 130 or any other location. Accordingly, in some examples, sensor data can correspond to a physical state of one or more actuators 130, a physical state of a portion of the exoskeleton system 100, a physical state of the exoskeleton system 100 generally, and the like. In some embodiments, the exoskeleton system 100 can include a global positioning system (GPS), camera, range sensing system, environmental sensors, elevation sensor, microphone, thermometer, or the like. In some embodiments, the exoskeleton system 100 can obtain sensor data from a user device such as a smartphone, or the like.

In some cases, it can be beneficial for the exoskeleton system 100 to generate or augment an understanding of a user 101 wearing the exoskeleton device 100, of the environment and/or operation of the exoskeleton system 100 through integrating various suitable sensors 515 into the exoskeleton system 100. One embodiment can include sensors 515 to measure and track biological indicators to observe various suitable aspects of user 101 (e.g., corresponding to fatigue and/or body vital functions) such as, body temperature, heart rate, respiratory rate, blood pressure, blood oxygenation saturation, expired CO₂, blood glucose level, gait speed, sweat rate, and the like.

In some embodiments, the exoskeleton system 100 can take advantage of the relatively close and reliable connectivity of such sensors 515 to the body of the user 101 to record system vitals and store them in an accessible format (e.g., at the exoskeleton device, a remote device, a remote server, or the like). Another embodiment can include environmental sensors 515 that can continuously or periodically measure the environment around the exoskeleton system 100 for various environmental conditions such as temperature, humidity, light level, barometric pressure, radioactivity, sound level, toxins, contaminants, or the like. In some examples, various sensors 515 may not be required for operation of the exoskeleton system 100 or directly used by operational control software, but can be stored for reporting to the user 101 (e.g., via an interface 515) or sending to a remote device, a remote server, or the like.

The pneumatic system 520 can comprise any suitable device or system that is operable to inflate and/or deflate the actuators 130 individually or as a group. For example, in one embodiment, the pneumatic system can comprise a diaphragm compressor as disclosed in related patent application Ser. No. 14/577,817 filed Dec. 19, 2014 or a pneumatic power transmission as discussed herein.

Turning to FIGS. 13a, 13b, 14a and 14b , examples of a leg actuator unit 110 can include the joint 125, bellows actuator 130, constraint ribs 135, and base plates 140. More specifically, FIG. 13a illustrates a side view of a leg actuator unit 110 in a compressed configuration and FIG. 13b illustrates a side view of the leg actuator unit 110 of FIG. 13a in an expanded configuration. FIG. 14a illustrates a cross-sectional side view of a leg actuator unit 110 in a compressed configuration and FIG. 14b illustrates a cross-sectional side view of the leg actuator unit 110 of FIG. 14a in an expanded configuration.

As shown in FIGS. 13a, 13b, 14a and 14b , the joint 125 can have a plurality of constraint ribs 135 extending from and coupled to the joint 125, which surround or abut a portion of the bellows actuator 130. For example, in some embodiments, constraint ribs 135 can abut the ends 132 of the bellows actuator 130 and can define some or all of the base plates 140 that the ends 132 of the bellows actuator 130 can push against. However, in some examples, the base plates 140 can be separate and/or different elements than the constraint ribs 135 (e.g., as shown in FIG. 1). Additionally, one or more constraint ribs 135 can be disposed between ends 132 of the bellows actuator 130. For example, FIGS. 13a, 13b, 14a and 14b illustrate one constraint rib 135 disposed between ends 132 of the bellows actuator 130; however, further embodiments can include any suitable number of constraint ribs 135 disposed between ends of the bellows actuator 130, including 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 50, 100 and the like. In some embodiments, constraint ribs can be absent.

As shown in cross sections of FIGS. 14a and 14b , the bellows actuator 130 can define a cavity 131 that can be filled with fluid (e.g., air), to expand the bellows actuator 130, which can cause the bellows to elongate along axis B as shown in FIGS. 13b and 14b . For example, increasing a pressure and/or volume of fluid in the bellows actuator 130 shown in FIG. 13a can cause the bellows actuator 130 to expand to the configuration shown in FIG. 13b . Similarly, increasing a pressure and/or volume of fluid in the bellows actuator 130 shown in FIG. 14a can cause the bellows actuator 130 to expand to the configuration shown in FIG. 14b . For clarity, the use of the term “bellows” is to describe a component in the described actuator unit 110 and is not intended to limit the geometry of the component. The bellows actuator 130 can be constructed with a variety of geometries including but not limited to a constant cylindrical tube, a cylinder of varying cross-sectional area, a 3-D woven geometry that inflates to a defined arc shape, and the like. The term ‘bellows’ should not be construed to necessary include a structure having convolutions.

Alternatively, decreasing a pressure and/or volume of fluid in the bellows actuator 130 shown in FIG. 13b can cause the bellows actuator 130 to contract to the configuration shown in FIG. 13a . Similarly, decreasing a pressure and/or volume of fluid in the bellows actuator 130 shown in FIG. 14b can cause the bellows actuator 130 to contract to the configuration shown in FIG. 14a . Such increasing or decreasing of a pressure or volume of fluid in the bellows actuator 130 can be performed by pneumatic system 520 and pneumatic lines 145 of the exoskeleton system 100, which can be controlled by the exoskeleton device 510 (see FIG. 5).

In one preferred embodiment, the bellows actuator 130 can be inflated with air; however, in further embodiments, any suitable fluid can be used to inflate the bellows actuator 130. For example, gasses including oxygen, helium, nitrogen, and/or argon, or the like can be used to inflate and/or deflate the bellows actuator 130. In further embodiments, a liquid such as water, an oil, or the like can be used to inflate the bellows actuator 130. Additionally, while some examples discussed herein relate to introducing and removing fluid from a bellows actuator 130 to change the pressure within the bellows actuator 130, further examples can include heating and/or cooling a fluid to modify a pressure within the bellows actuator 130.

As shown in FIGS. 13a, 13b, 14a and 14b , the constraint ribs 135 can support and constrain the bellows actuator 130. For example, inflating the bellows actuator 130 causes the bellows actuator 130 to expand along a length of the bellows actuator 130 and also cause the bellows actuator 130 to expand radially. The constraint ribs 135 can constrain radial expansion of a portion of the bellows actuator 130. Additionally, as discussed herein, the bellows actuator 130 comprise a material that is flexible in one or more directions and the constraint ribs 135 can control the direction of linear expansion of the bellows actuator 130. For example, in some embodiments, without constraint ribs 135 or other constraint structures the bellows actuator 130 would herniate or bend out of axis uncontrollably such that suitable force would not be applied to the base plates 140 such that the arms 115, 120 would not be suitably or controllably actuated. Accordingly, in various embodiments, the constraint ribs 135 can be desirable to generate a consistent and controllable axis of expansion B for the bellows actuator 130 as they are inflated and/or deflated.

In some examples, the bellows actuator 130 in a deflated configuration can substantially extend past a radial edge of the constraint ribs 135 and can retract during inflation to extend less past the radial edge of the constraint ribs 135, to extend to the radial edge of the constraint ribs 135, or not to extend less past the radial edge of the constraint ribs 135. For example, FIG. 14a illustrates a compressed configuration of the bellows actuator 130 where the bellows actuator 130 substantially extend past a radial edge of the constraint ribs 135 and FIG. 14b illustrates the bellows actuator 130 retracting during inflation to extend less past the radial edge of the constraint ribs 135 in an inflated configuration of the bellows actuator 130.

Similarly, FIG. 15a illustrates a top view of a compressed configuration of bellows actuator 130 where the bellows actuator 130 substantially extend past a radial edge of constraint ribs 135 and FIG. 15b illustrates a top view where the bellows actuator 130 retract during inflation to extend less past the radial edge of the constraint ribs 135 in an inflated configuration of the bellows actuator 130.

Constraint ribs 135 can be configured in various suitable ways. For example, FIGS. 15a, 15b and 16 illustrate a top view of an example embodiment of a constraint rib 135 having a pair of rib arms 136 that extend from the joint structure 125 and couple with a circular rib ring 137 that defines a rib cavity 138 through which a portion of the bellows actuator 130 can extend (e.g., as shown in FIGS. 14a, 14b, 15a and 15b ). In various examples, the one or more constraint ribs 135 can be a substantially planar element with the rib arms 136 and rib ring 137 being disposed within a common plane.

In further embodiments, the one or more constraint ribs 135 can have any other suitable configuration. For example, some embodiments can have any suitable number of rib arms 136, including one, two, three, four, five, or the like. Additionally, the rib ring 137 can have various suitable shapes and need not be circular, including one or both of an inner edge that defines the rib cavity 138 or an outer edge of the rib ring 137.

In various embodiments, the constraining ribs 135 can be configured to direct the motion of the bellows actuator 130 through a swept path about some instantaneous center (which may or may not be fixed in space) and/or to prevent motion of the bellows actuator 130 in undesired directions, such as out-of-plane buckling. As a result, the number of constraining ribs 135 included in some embodiments can vary depending on the specific geometry and loading of the leg actuator unit 110. Examples can range from one constraining rib 135 up to any suitable number of constraining ribs 135; accordingly, the number of constraining ribs 135 should not be taken to limit the applicability of the invention. Additionally, constraining ribs 135 can be absent in some embodiments.

The one or more constraining ribs 135 can be constructed in a variety of ways. For example the one or more constraining ribs 135 can vary in construction on a given leg actuator unit 110, and/or may or may not require attachment to the joint structure 125. In various embodiments, the constraining ribs 135 can be constructed as an integral component of a central rotary joint structure 125. An example embodiment of such a structure can include a mechanical rotary pin joint, where the constraining ribs 135 are connected to and can pivot about the joint 125 at one end of the joint structure 125, and are attached to an inextensible outer layer of the bellows actuator 130 at the other end. In another set of embodiments, the constraining ribs 135 can be constructed in the form of a single flexural structure that directs the motion of the bellows actuator 130 throughout the range of motion for the leg actuator unit 110. Another example embodiment uses a flexural constraining rib 135 that is not connected integrally to the joint structure 125 but is instead attached externally to a previously assembled joint structure 125. Another example embodiment can comprise the constraint ribs 135 being composed of pieces of fabric wrapped around the bellows actuator 130 and attached to the joint structure 125, acting like a hammock to restrict and/or guide the motion of the bellows actuator 130. There are additional methods available for constructing the constraining ribs 135 that can be used in additional embodiments that include but are not limited to a linkage, a rotational flexure connected around the joint structure 125, and the like.

In some examples, a design consideration for constraining ribs 135 can be how the one or more constraining ribs 135 interact with the bellows actuator 130 to guide the path of the bellows actuator 130. In various embodiments, the constraining ribs 135 can be fixed to the bellows actuator 130 at predefined locations along the length of the bellows actuator 130. One or more constraining ribs 135 can be coupled to the bellows actuator 130 in various suitable ways, including but not limited to sewing, mechanical clamps, geometric interference, direct integration, and the like. In other embodiments, the constraining ribs 135 can be configured such that the constraining ribs 135 float along the length of the bellows actuator 130 and are not fixed to the bellows actuator 130 at predetermined connection points. In some embodiments, the constraining ribs 135 can be configured to restrict a cross sectional area of the bellows actuator 130. An example embodiment can include a tubular bellows actuator 130 attached to a constraining rib 135 that has an oval cross section, which in some examples can be a configuration to reduce the width of the bellows actuator 130 at that location when the bellows actuator 130 is inflated.

The bellows actuator 130 can have various functions in some embodiments, including containing operating fluid of the leg actuator unit 110, resisting forces associated with operating pressure of the leg actuator unit 110, and the like. In various examples, the leg actuator unit 110 can operate at a fluid pressure above, below or at about ambient pressure. In various embodiments, bellows actuator 130 can comprise one or more flexible, yet inextensible or practically inextensible materials in order to resist expansion (e.g., beyond what is desired in directions other than an intended direction of force application or motion) of the bellows actuator 130 beyond what is desired when pressurized above ambient pressure. Additionally, the bellows actuator 130 can comprise an impermeable or semi-impermeable material in order to contain the actuator fluid.

For example, in some embodiments, the bellows actuator 130 can comprise a flexible sheet material such as woven nylon, rubber, polychloroprene, a plastic, latex, a fabric, or the like. Accordingly, in some embodiments, bellows actuator 130 can be made of a planar material that is substantially inextensible along one or more plane axes of the planar material while being flexible in other directions. For example, FIG. 18 illustrates a side view of a planar material 1800 (e.g., a fabric) that is substantially inextensible along axis X that is coincident with the plane of the material 1800, yet flexible in other directions, including axis Z. In the example of FIG. 18, the material 1800 is shown flexing upward and downward along axis Z while being inextensible along axis X. In various embodiments, the material 1800 can also be inextensible along an axis Y (not shown) that is also coincident with the plane of the material 1800 like axis X and perpendicular to axis X.

In some embodiments, the bellows actuator 130 can be made of a non-planar woven material that is inextensible along one or more axes of the material. For example, in one embodiment the bellows actuator 130 can comprise a woven fabric tube. Woven fabric material can provide inextensibility along the length of the bellows actuator 130 and in the circumferential direction. Such embodiments can still be able to be configured along the body of the user 101 to align with the axis of a desired joint on the body 101 (e.g., the knee 103).

In various embodiments, the bellows actuator 130 can develop its resulting force by using a constrained internal surface length and/or external surface length that are a constrained distance away from each other (e.g. due to an inextensible material as discussed above). In some examples, such a design can allow the actuator to contract on bellows actuator 130, but when pressurized to a certain threshold, the bellows actuator 130 can direct the forces axially by pressing on the plates 140 of the leg actuator unit 110 because there is no ability for the bellows actuator 130 to expand further in volume otherwise due to being unable to extend its length past a maximum length defined by the body of the bellows actuator 130.

In other words, the bellows actuator 130 can comprise a substantially inextensible textile envelope that defines a chamber that is made fluid-impermeable by a fluid-impermeable bladder contained in the substantially inextensible textile envelope and/or a fluid-impermeable structure incorporated into the substantially inextensible textile envelope. The substantially inextensible textile envelope can have a predetermined geometry and a non-linear equilibrium state at a displacement that provides a mechanical stop upon pressurization of the chamber to prevent excessive displacement of the substantially inextensible textile actuator.

In some embodiments, the bellows actuator 130 can include an envelope that consists or consists essentially of inextensible textiles (e.g., inextensible knits, woven, non-woven, etc.) that can prescribe various suitable movements as discussed herein. Inextensible textile bellows actuator 130 can be designed with specific equilibrium states (e.g., end states or shapes where they are stable despite increasing pressure), pressure/stiffness ratios, and motion paths. Inextensible textile bellows actuator 130 in some examples can be configured accurately delivering high forces because inextensible materials can allow greater control over directionality of the forces.

Accordingly, some embodiments of inextensible textile bellows actuator 130 can have a pre-determined geometry that produces displacement mostly via a change in the geometry between the uninflated shape and the pre-determined geometry of its equilibrium state (e.g., fully inflated shape) due to displacement of the textile envelope rather than via stretching of the textile envelope during a relative increase in pressure inside the chamber; in various embodiments, this can be achieved by using inextensible materials in the construction of the envelope of the bellows actuator 130. As discussed herein, in some examples “inextensible” or “substantially inextensible” can be defined as expansion by no more than 10%, no more than 5%, or no more than 1% in one or more direction.

FIG. 17a illustrates a cross-sectional view of a pneumatic actuator unit 110 including bellows actuator 130 in accordance with another embodiment and FIG. 17b illustrates a side view of the pneumatic actuator unit 110 of FIG. 17a in an expanded configuration showing the cross section of FIG. 17a . As shown in FIG. 17a , the bellows actuator 130 can comprise an internal first layer 132 that defines the bellows cavity 131 and can comprise an outer second layer 133 with a third layer 134 disposed between the first and second layers 132, 133. Throughout this description, the use of the term “layer” to describe the construction of the bellows actuator 130 should not be viewed as limiting to the design. The use of ‘layer’ can refer to a variety of designs including but not limited to: a planar material sheet, a wet film, a dry film, a rubberized coating, a co-molded structure, and the like.

In some examples, the internal first layer 132 can comprise a material that is impermeable or semi-permeable to the actuator fluid (e.g., air) and the external second layer 133 can comprise an inextensible material as discussed herein. For example, as discussed herein, an impermeable layer can refer to an impermeable or semi-permeable layer and an inextensible layer can refer to an inextensible or a practically inextensible layer.

In some embodiments comprising two or more layers, the internal layer 132 can be slightly oversized compared to an inextensible outer second layer 133 such that the internal forces can be transferred to the high-strength inextensible outer second layer 133. One embodiment comprises a bellows actuator 130 with an impermeable polyurethane polymer film inner first layer 132 and a woven nylon braid as the outer second layer 133.

The bellows actuator 130 can be constructed in various suitable ways in further embodiments, which can include a single-layer design that is constructed of a material that provides both fluid impermeability and that is sufficiently inextensible. Other examples can include a complex bellows assembly that comprises multiple laminated layers that are fixed together into a single structure. In some examples, it can be necessary to limit the deflated stack height of the bellows actuator 130 to maximize the range of motion of the leg actuator unit 110. In such an example, it can be desirable to select a low-thickness fabric that meets the other performance needs of the bellows actuator 130.

In yet another embodiment, it can be desirable to reduce friction between the various layers of the bellows actuator 130. In one embodiment, this can include the integration of a third layer 134 that acts as an anti-abrasive and/or low friction intermediate layer between the first and second layers 132, 133. Other embodiments can reduce the friction between the first and second layers 132, 133 in alternative or additional ways, including but not limited to the use of a wet lubricant, a dry lubricant, or multiple layers of low friction material. Accordingly, while the example of FIG. 15a illustrates an example of a bellows actuator 130 comprising three layers 132, 133, 134, further embodiments can include a bellows actuator 130 having any suitable number of layers, including one, two, three, four, five, ten, fifteen, twenty five, and the like. Such one or more layers can be coupled along adjoining faces in part or in whole, with some examples defining one or more cavities between layers. In such examples, material such as lubricants or other suitable fluids can be disposed in such cavities or such cavities can be effectively empty. Additionally, as described herein, one or more layers (e.g., the third layer 134) need not be a sheet or planar material layer as shown in some examples and can instead comprise a layer defined by a fluid. For example, in some embodiments, the third layer 134 can be defined by a wet lubricant, a dry lubricant, or the like.

The inflated shape of the bellows actuator 130 can be important to the operation of the bellows actuator 130 and/or leg actuator unit 110 in some embodiments. For example, the inflated shape of the bellows actuator 130 can be affected through the design of both an impermeable and inextensible portion of the bellows actuator 130 (e.g., the first and second layer 132, 133). In various embodiments, it can be desirable to construct one or more of the layers 132, 133, 134 of the bellows actuator 130 out of various two-dimensional panels that may not be intuitive in a deflated configuration.

In some embodiments, one or more impermeable layers can be disposed within the bellows cavity 131 and/or the bellows actuator 130 can comprise a material that is capable of holding a desired fluid (e.g., a fluid impermeable first internal layer 132 as discussed herein). The bellows actuator 130 can comprise a flexible, elastic, or deformable material that is operable to expand and contract when the bellows actuator 130 are inflated or deflated as described herein. In some embodiments, the bellows actuator 130 can be biased toward a deflated configuration such that the bellows actuator 130 is elastic and tends to return to the deflated configuration when not inflated. Additionally, although bellows actuator 130 shown herein are configured to expand and/or extend when inflated with fluid, in some embodiments, bellows actuator 130 can be configured to shorten and/or retract when inflated with fluid in some examples. Also, the term “bellows” as used herein should not be construed to be limiting in any way. For example the term “bellows” as used herein should not be construed to require elements such as convolutions or other such features (although convoluted bellows actuator 130 can be present in some embodiments). As discussed herein, bellows actuator 130 can take on various suitable shapes, sizes, proportions and the like.

The bellows actuator 130 can vary significantly across various embodiments, so the present examples should not be construed to be limiting. One preferred embodiment of a bellows actuator 130 includes fabric-based pneumatic actuator configured such that it provides knee extension torque as discussed herein. Variants of this embodiment can exist to tailor the actuator to provide the desired performance characteristics of the actuators such as a fabric actuator that is not of a uniform cross-section. Other embodiments can use an electro-mechanical actuator configured to provide flexion and extension torques at the knee instead of or in addition to a fluidic bellows actuator 130. Various embodiments can include but are not limited to designs that incorporate combinations of electromechanical, hydraulic, pneumatic, electro-magnetic, or electro-static for positive power or negative power assistance of extension or flexion of a lower extremity joint.

The actuator bellows actuator 130 can also be located in a variety of locations as required by the specific design. One embodiment places the bellows actuator 130 of a powered knee brace component located in line with the axis of the knee joint and positioned parallel to the joint itself. Various embodiments include but are not limited to, actuators configured in series with the joint, actuators configured anterior to the joint, and actuators configured to rest around the joint.

Various embodiments of the bellows actuator 130 can include secondary features that augment the operation of the actuation. One such embodiment is the inclusion of user-adjustable mechanical hard end stops to limit the allowable range of motion to the bellows actuator 130. Various embodiments can include but are not limited to the following extension features: the inclusion of flexible end stops, the inclusion of an electromechanical brake, the inclusion of an electro-magnetic brake, the inclusion of a magnetic brake, the inclusion of a mechanical disengage switch to mechanically decouple the joint from the actuator, or the inclusion of a quick release to allow for quick changing of actuator components.

In various embodiments, the bellows actuator 130 can comprise a bellows and/or bellows system as described in related U.S. patent application Ser. No. 14/064,071 filed Oct. 25, 2013, which issued as U.S. Pat. No. 9,821,475; as described in U.S. patent application Ser. No. 14/064,072 filed Oct. 25, 2013; as described in U.S. patent application Ser. No. 15/823,523 filed Nov. 27, 2017; or as described in U.S. patent application Ser. No. 15/472,740 filed Mar. 29, 2017.

In some applications, the design of the fluidic actuator unit 110 can be adjusted to expand its capabilities. One example of such a modification can be made to tailor the torque profile of a rotary configuration of the fluidic actuator unit 110 such that the torque changes as a function of the angle of the joint structure 125. To accomplish this in some examples, the cross-section of the bellows actuator 130 can be manipulated to enforce a desired torque profile of the overall fluidic actuator unit 110. In one embodiment, the diameter of the bellows actuator 130 can be reduced at a longitudinal center of the bellows actuator 130 to reduce the overall force capabilities at the full extension of the bellows actuator 130. In yet another embodiment, the cross-sectional areas of the bellows actuator 130 can be modified to induce a desired buckling behavior such that the bellows actuator 130 does not get into an undesirable configuration. In an example embodiment, the end configurations of the bellows actuator 130 of a rotary configuration can have the area of the ends reduced slightly from the nominal diameter to provide for the end portions of the bellows actuator 130 to buckle under loading until the actuator unit 110 extends beyond a predetermined joint angle, at which point the smaller diameter end portion of the bellows actuator 130 would begin to inflate.

In other embodiments, this same capability can be developed by modifying the behavior of the constraining ribs 135. As an example embodiment, using the same example bellows actuator 130 as discussed in the previous embodiment, two constraining ribs 135 can fixed to such bellows actuator 130 at evenly distributed locations along the length of the bellows actuator 130. In some examples, a goal of resisting a partially inflated buckling can be combated by allowing the bellows actuator 130 to close in a controlled manner as the actuator unit 110 closes. The constraining ribs 135 can be allowed to get closer to the joint structure 125 but not closer to each other until they have bottomed out against the joint structure 125. This can allow the center portion of the bellows actuator 130 to remain in a fully inflated state which can be the strongest configuration of the bellows actuator 130 in some examples.

In further embodiments, it can be desirable to optimize the fiber angle of the individual braid or weave of the bellows actuator 130 in order to tailor specific performance characteristics of the bellows actuator 130 (e.g., in an example where a bellows actuator 130 includes inextensibility provided by a braided or woven fabric). In other embodiments, the geometry of the bellows actuator 130 of the actuator unit 110 can be manipulated to allow the robotic exoskeleton system 100 to operate with different characteristics. Example methods for such modification can include but are not limited to the following: the use of smart materials on the bellows actuator 130 to manipulate the mechanical behavior of the bellows actuator 130 on command; or the mechanical modification of the geometry of the bellows actuator 130 through means such as shortening the operating length and/or reducing the cross sectional area of the bellows actuator 130.

In further examples, a fluidic actuator unit 110 can comprise a single bellows actuator 130 or a combination of multiple bellows actuator 130, each with its own composition, structure, and geometry. For example, some embodiments can include multiple bellows actuator 130 disposed in parallel or concentrically on the same joint assembly 125 that can be engaged as needed. In one example embodiment, a joint assembly 125 can be configured to have two bellows actuator 130 disposed in parallel directly next to each other. The exoskeleton system 100 can selectively choose to engage each bellows actuator 130 as needed to allow for various amounts of force to be output by the same fluidic actuator unit 110 in a desirable mechanical configuration.

In further embodiments, a fluidic actuator unit 110 can include various suitable sensors to measure mechanical properties of the bellows actuator 130 or other portions of the fluidic actuator unit 110 that can be used to directly or indirectly estimate pressure, force, or strain in the bellows actuator 130 or other portions of the fluidic actuator unit 110. In some examples, sensors located at the fluidic actuator unit 110 can be desirable due to the difficulty in some embodiments associated with the integration of certain sensors into a desirable mechanical configuration while others may be more suitable. Such sensors at the fluidic actuator unit 110 can be operably connected to the exoskeleton device 610 (see FIG. 6) and the exoskeleton device 610 can use data from such sensors at the fluidic actuator unit 110 to control the exoskeleton system 100.

As discussed herein, various suitable exoskeleton systems 100 can be used in various suitable ways and for various suitable applications. However, such examples should not be construed to be limiting on the wide variety of exoskeleton systems 100 or portions thereof that are within the scope and spirit of the present disclosure. Accordingly, exoskeleton systems 100 that are more or less complex than the examples of FIGS. 1-10 are within the scope of the present disclosure.

Additionally, while various examples relate to an exoskeleton system 100 associated with the legs or lower body of a user, further examples can be related to any suitable portion of a user body including the torso, arms, head, legs, or the like. Also, while various examples relate to exoskeletons, it should be clear that the present disclosure can be applied to other similar types of technology, including prosthetics, body implants, robots, or the like. Further, while some examples can relate to human users, other examples can relate to animal users, robot users, various forms of machinery, or the like.

The described embodiments are susceptible to various modifications and alternative forms, and specific examples thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the described embodiments are not to be limited to the particular forms or methods disclosed, but to the contrary, the present disclosure is to cover all modifications, equivalents, and alternatives. Additionally, elements of a given embodiment should not be construed to be applicable to only that example embodiment and therefore elements of one example embodiment can be applicable to other embodiments. Additionally, elements that are specifically shown in example embodiments should be construed to cover embodiments that comprise, consist essentially of, or consist of such elements, or such elements can be explicitly absent from further embodiments. Accordingly, the recitation of an element being present in one example should be construed to support some embodiments where such an element is explicitly absent. 

What is claimed is:
 1. An exoskeleton system comprising: a left and right leg actuator unit that are respectively coupled to a left and right leg of a user over clothing of the user, the left and right leg actuator units each including: an upper arm and a lower arm that are rotatably coupled via a rotatable joint, the rotatable joint positioned laterally adjacent to a knee of the user with the upper arm coupled about an upper-leg portion of the user above the knee and with the lower arm coupled about a lower-leg portion of the user below the knee, the upper arm coupled to the upper-leg portion above the knee via a first set of couplers that includes a first upper-leg coupler joined to the upper arm by a rigid upper-leg brace disposed on a lateral side of the upper-leg portion, with a strap of the first upper-leg coupler extending around the upper-leg portion, the upper arm coupled to the rigid upper-leg brace on a lateral side of the upper-leg portion and configured to transfer force generated by the upper arm to the upper-leg portion of the leg of the user, the lower arm coupled to the lower-leg portion below the knee via a second set of couplers that includes a first and second lower-leg coupler associated with a rigid lower-leg brace disposed on and engaging a lateral side of the lower-leg portion of the leg, the lower arm coupled to the rigid lower-leg brace on a lateral side of the lower-leg portion of the leg and configured to transfer force generated by the lower arm to the lower-leg portion of the leg, the rigid lower-leg brace extending downward from a coupling with the lower arm at a lateral position on the lower-leg portion of the leg, with a portion of the rigid lower-leg brace curving toward a posterior of the lower-leg portion to attachments that couple one or more portions of the first and second lower-leg couplers to the rigid lower-leg brace, wherein the first lower-leg coupler comprises a calf-coupling assembly that includes a calf brace that is coupled to the rigid lower-leg brace via a first, second and third calf strap, the first and second calf straps extending horizontally from opposing lateral sides of an upper portion of the rigid lower-leg brace from an internal face of the rigid lower-leg brace, and the third calf strap extending vertically from a lower posterior portion of the rigid lower-leg brace from an internal face of the rigid lower-leg brace where the third calf strap is coupled to the rigid lower-leg brace via a first set of one or more attachments, and wherein the second lower-leg coupler comprises an ankle-coupling assembly that includes a cuff that extends around and surrounds the lower-leg portion above the ankle of the user and held via an ankle strap, the cuff coupled to the rigid lower-leg brace via one or more coupling tabs that extend vertically from the cuff, with the one or more coupling tabs coupled to the rigid lower-leg brace via a second set of one or more attachments on an internal face of the rigid lower-leg brace; a bellows actuator that extends between the upper arm and lower arm; and one or more sets of pneumatic lines coupled to the bellows actuator to introduce pneumatic fluid to and remove fluid from the bellows actuator to cause the bellows actuator to expand and contract and move the upper arm and lower arm.
 2. The exoskeleton system of claim 1, wherein the cuff extends around and surrounds the lower-leg portion at a supra-malleolar location that is located above a malleolus of the ankle and below a bulk of the calf muscle in a narrowing diameter portion of the lower-leg portion of the user.
 3. The exoskeleton system of claim 1, wherein one or more coupling tabs are inextensible along a length of the one or more coupling tabs that defines an axis of coupling between the rigid lower-leg brace and the respective one or more coupling tabs, wherein the one or more coupling tabs are flexible about the length of the one or more coupling tabs that defines the axis of coupling between the rigid lower-leg brace and the respective one or more coupling tabs, and wherein the inextensibility along a length of the one or more coupling tabs and the flexibility about the length of the one or more coupling tabs causes the one or more coupling tabs to provide resistance to translation of the cuff relative to the rigid lower-leg brace while also allowing rotational movement between the rigid lower-leg brace and the cuff that extends around and surrounds the lower-leg portion.
 4. The exoskeleton system of claim 1, wherein the left and right leg actuator units each further include one or more adjustment elements for anatomical variations in varus or valgus angles in the lower-leg portion of the leg of the user, the one or more adjustment elements including a first adjustment element that comprises a cross-strap that spans the knee joint of the user, the first adjustment element configured to be tightened to provide a moment across the knee joint of the user in a frontal plane to vary a nominal resting angle of the respective left and right leg actuator unit on the respective legs of the user.
 5. The exoskeleton system of claim 1, wherein the left leg actuator unit includes a first quick-doff feature that allows the left leg actuator unit to be physically disengaged from the user by causing the first upper-leg coupler and the first and second lower-leg couplers of the left leg actuator unit to be collectively physically disengaged substantially simultaneously; and wherein the right leg actuator unit includes a second quick-doff feature that allows the right leg actuator unit to be physically disengaged from the user by causing the first upper-leg coupler and the first and second lower-leg couplers of the right leg actuator unit to be collectively physically disengaged substantially simultaneously.
 6. The exoskeleton system of claim 1, wherein the left and right leg actuator units comprise an active actuation fit system, the active actuation fit system configured to automatically tighten and loosen the first upper-leg coupler and the first and second lower-leg couplers, the active actuation fit system being controlled by an exoskeleton device in response to data obtained regarding fit of the left and right leg actuator units on the legs of the user and being controlled by the exoskeleton device based on comparing the data regarding the fit of the left and right leg actuator units on the legs of the user to a set of fit parameters for the fit of the left and right leg actuator units on the legs of the user.
 7. An exoskeleton system comprising: a leg actuator unit that is configured to be coupled to a leg of a user over clothing of the user, the leg actuator unit including: an upper arm and a lower arm that are rotatably coupled via a rotatable joint, the rotatable joint configured to be positioned at a knee of the user with the upper arm coupled about an upper-leg portion of the user above the knee and with the lower arm coupled about a lower-leg portion of the user below the knee, the upper arm configured to be coupled to the upper-leg portion above the knee via a first set of couplers that includes a first upper-leg coupler joined to the upper arm by a rigid upper-leg brace configured to be disposed on a lateral side of the upper-leg portion, with a strap of the first upper-leg coupler extending around the upper-leg portion, the upper arm coupled to the rigid upper-leg brace on a lateral side of the upper-leg portion and configured to transfer force generated by the upper arm to the upper-leg portion of the leg of the user, the lower arm configured to be coupled to the lower-leg portion below the knee via a second set of couplers that includes a first and second lower-leg coupler associated with a rigid lower-leg brace configured to be disposed on and engaging a lateral side of the lower-leg portion of the leg, the lower arm configured to be coupled to the rigid lower-leg brace on a lateral side of the lower-leg portion of the leg and configured to transfer force generated by the lower arm to the lower-leg portion of the leg, the rigid lower-leg brace extending from a coupling with the lower arm, with a portion of the rigid lower-leg brace curving to attachments that couple one or more portions of the first and second lower-leg couplers to the rigid lower-leg brace, and a bellows actuator that extends between the upper arm and lower arm, the bellows actuator configurable to expand and contract and move the upper arm and lower arm.
 8. The exoskeleton system of claim 7, wherein the first lower-leg coupler comprises a calf-coupling assembly that includes a calf brace that is coupled to the rigid lower-leg brace via a first, second and third calf strap, the first and second calf straps extending from opposing lateral sides of an upper portion of the rigid lower-leg brace, and the third calf strap extending vertically from a lower posterior portion of the rigid lower-leg brace where the third calf strap is coupled to the rigid lower-leg brace via a set of one or more attachments.
 9. The exoskeleton system of claim 7, wherein the second lower-leg coupler comprises an ankle-coupling assembly that includes a cuff configured to extend around and surround the lower-leg portion above the ankle of the user, the cuff coupled to the rigid lower-leg brace via one or more coupling tabs that extend from the cuff, with the one or more coupling tabs coupled to the rigid lower-leg brace via a second set of one or more attachments.
 10. The exoskeleton system of claim 9, wherein the cuff extends around and surrounds the lower-leg portion at a supra-malleolar location that is located above a malleolus of the ankle and below a bulk of the calf muscle in a narrowing diameter portion of the lower-leg portion of the user.
 11. The exoskeleton system of claim 9, wherein one or more coupling tabs are inextensible along a length of the one or more coupling tabs that defines an axis of coupling between the rigid lower-leg brace and the respective one or more coupling tabs, wherein the one or more coupling tabs are flexible about the length of the one or more coupling tabs that defines the axis of coupling between the rigid lower-leg brace and the respective one or more coupling tabs, and wherein the inextensibility along a length of the one or more coupling tabs and the flexibility about the length of the one or more coupling tabs causes the one or more coupling tabs to provide resistance to translation of the second lower-leg coupler relative to the rigid lower-leg brace while also allowing rotational movement between the rigid lower-leg brace and the second lower-leg coupler.
 12. The exoskeleton system of claim 9, wherein the leg actuator unit further includes one or more adjustment elements for anatomical variations in the lower-leg portion of the leg of the user, the one or more adjustment elements including a first adjustment element that comprises a cross-strap that is configured to span the knee joint of the user, the first adjustment element configured to be tightened to provide a moment across the knee joint of the user in a frontal plane to vary a nominal resting angle of the leg actuator unit on the leg of the user.
 13. The exoskeleton system of claim 7, wherein the leg actuator unit includes a quick-doff feature that allows the leg actuator unit to be physically disengaged from the user by causing the first upper-leg coupler and the first and second lower-leg couplers of the leg actuator unit to be collectively physically disengaged.
 14. The exoskeleton system of claim 7, wherein the leg actuator unit comprises an active actuation fit system, the active actuation fit system configured to automatically tighten and loosen the first upper-leg coupler and the first and second lower-leg couplers.
 15. An exoskeleton system comprising: a leg actuator unit that is configured to be coupled to a leg of a user, the leg actuator unit including: an upper arm and a lower arm that are rotatably coupled via a rotatable joint, the rotatable joint configured to be positioned at a knee of the user with the upper arm coupled about an upper-leg portion of the user above the knee and with the lower arm coupled about a lower-leg portion of the user below the knee, the upper arm configured to be coupled to the upper-leg portion above the knee via a first set of couplers that includes a first upper-leg coupler joined to the upper arm by an upper-leg brace configured to be disposed on the upper-leg portion, the upper arm coupled to the upper-leg brace on the upper-leg portion and configured to transfer force generated by the upper arm to the upper-leg portion of the leg of the user, the lower arm configured to be coupled to the lower-leg portion below the knee via a second set of couplers that includes one or more lower-leg couplers associated with a lower-leg brace configured to be disposed on and engaging the lower-leg portion of the leg, the lower arm configured to be coupled to the lower-leg brace on the lower-leg portion of the leg and configured to transfer force generated by the lower arm to the lower-leg portion of the leg, the lower-leg brace extending from a coupling with the lower arm, and an actuator that extends between the upper arm and lower arm, the actuator configurable to move the upper arm and lower arm.
 16. The exoskeleton system of claim 15, wherein one or more lower-leg couplers comprise an ankle-coupling assembly that includes a cuff configured to extend around and surround the lower-leg portion above the ankle of the user, the cuff coupled to the lower-leg brace via one or more coupling tabs that extend from the cuff, with the one or more coupling tabs coupled to the lower-leg brace via a set of one or more attachments.
 17. The exoskeleton system of claim 16, wherein one or more coupling tabs are inextensible along a length of the one or more coupling tabs that defines an axis of coupling between the lower-leg brace and the respective one or more coupling tabs, and wherein the one or more coupling tabs are flexible about the length of the one or more coupling tabs that defines the axis of coupling between the lower-leg brace and the respective one or more coupling tabs.
 18. The exoskeleton system of claim 15, wherein the leg actuator unit further includes one or more adjustment elements including a first adjustment element that comprises a cross-strap configured to span the knee joint of the user, the first adjustment element configured to provide a moment across the knee joint of the user to vary a nominal resting angle of the leg actuator unit on the leg of the user.
 19. The exoskeleton system of claim 15, wherein the leg actuator unit includes a quick-doff feature that allows the leg actuator unit to be physically disengaged from the user by causing the first upper-leg coupler and the one or more lower-leg couplers of the leg actuator unit to be collectively disengaged.
 20. The exoskeleton system of claim 15, wherein the leg actuator unit comprises an active actuation fit system, the active actuation fit system configured to automatically configure at least one of the first upper-leg coupler and the one or more lower-leg couplers. 